RSS Alerts from National Cyber Awareness System
Summary
Note: This joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and learn more about other ransomware threats and no-cost resources.
The Federal Bureau of Investigation (FBI), Cybersecurity and Infrastructure Security Agency (CISA), and Australian Cyber Security Centre (ACSC) are releasing this joint Cybersecurity Advisory to disseminate known BianLian ransomware and data extortion group IOCs and TTPs identified through FBI and ACSC investigations as of March 2023.
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Actions to take today to mitigate cyber threats from BianLian ransomware and data extortion: |
BianLian is a ransomware developer, deployer, and data extortion cybercriminal group that has targeted organizations in multiple U.S. critical infrastructure sectors since June 2022. They have also targeted Australian critical infrastructure sectors in addition to professional services and property development. The group gains access to victim systems through valid Remote Desktop Protocol (RDP) credentials, uses open-source tools and command-line scripting for discovery and credential harvesting, and exfiltrates victim data via File Transfer Protocol (FTP), Rclone, or Mega. BianLian group actors then extort money by threatening to release data if payment is not made. BianLian group originally employed a double-extortion model in which they encrypted victims’ systems after exfiltrating the data; however, around January 2023, they shifted to primarily exfiltration-based extortion.
FBI, CISA, and ACSC encourage critical infrastructure organizations and small- and medium-sized organizations to implement the recommendations in the Mitigations section of this advisory to reduce the likelihood and impact of BianLian and other ransomware incidents.
Download the PDF version of this report (710kb):
For a downloadable copy of IOCs (35kb), see:
Technical Details
Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 13. See the MITRE ATT&CK® Tactics and Techniques section for a table of the threat actors’ activity mapped to MITRE ATT&CK® Tactics and Techniques. For assistance with mapping malicious cyber activity to the MITRE ATT&CK framework, see CISA and MITRE ATT&CK’s Best Practices for MITRE ATT&CK Mapping and CISA’s Decider Tool.
BianLian is a ransomware developer, deployer, and data extortion cybercriminal group. FBI observed BianLian group targeting organizations in multiple U.S. critical infrastructure sectors since June 2022. In Australia, ACSC has observed BianLian group predominately targeting private enterprises, including one critical infrastructure organization. BianLian group originally employed a double-extortion model in which they exfiltrated financial, client, business, technical, and personal files for leverage and encrypted victims’ systems. In 2023, FBI observed BianLian shift to primarily exfiltration-based extortion with victims’ systems left intact, and ACSC observed BianLian shift exclusively to exfiltration-based extortion. BianLian actors warn of financial, business, and legal ramifications if payment is not made.
Initial Access
BianLian group actors gain initial access to networks by leveraging compromised Remote Desktop Protocol (RDP) credentials likely acquired from initial access brokers [T1078],[T1133] or via phishing [T1566].
Command and Control
BianLian group actors implant a custom backdoor specific to each victim written in Go (see the Indicators of Compromise Section for an example) [T1587.001] and install remote management and access software—e.g., TeamViewer, Atera Agent, SplashTop, AnyDesk—for persistence and command and control [T1105],[T1219].
FBI also observed BianLian group actors create and/or activate local administrator accounts [T1136.001] and change those account passwords [T1098].
Defense Evasion
BianLian group actors use PowerShell [T1059.001] and Windows Command Shell [T1059.003] to disable antivirus tools [T1562.001], specifically Windows defender and Anti-Malware Scan Interface (AMSI). BianLian actors modify the Windows Registry [T1112] to disable tamper protection for Sophos SAVEnabled, SEDEenabled, and SAVService services, which enables them to uninstall these services. See Appendix: Windows PowerShell and Command Shell Activity for additional information, including specific commands they have used.
Discovery
BianLian group actors use a combination of compiled tools, which they first download to the victim environment, to learn about the victim’s environment. BianLian group actors have used:
- Advanced Port Scanner, a network scanner used to find open ports on network computers and retrieve versions of programs running on the detected ports [T1046].
- SoftPerfect Network Scanner (netscan.exe), a network scanner that can ping computers, scan ports, and discover shared folders [T1135].
- SharpShares to enumerate accessible network shares in a domain.
- PingCastle to enumerate Active Directory (AD) [T1482]. PingCastle provides an AD map to visualize the hierarchy of trust relationships.
BianLian actors also use native Windows tools and Windows Command Shell to:
- Query currently logged-in users [T1033].
- Query the domain controller to identify:
- All groups [T1069.002].
- Accounts in the Domain Admins and Domain Computers groups [1087.002].
- All users in the domain.
- Retrieve a list of all domain controllers and domain trusts.
- Identify accessible devices on the network [T1018].
See Appendix: Windows PowerShell and Command Shell Activity for additional information, including specific commands they have used.
Credential Access
BianLian group uses valid accounts for lateral movement through the network and to pursue other follow-on activity. To obtain the credentials, BianLian group actors use Windows Command Shell to find unsecured credentials on the local machine [T1552.001]. FBI also observed BianLian harvest credentials from the Local Security Authority Subsystem Service (LSASS) memory [T1003.001], download RDP Recognizer (a tool that could be used to brute force RDP passwords or check for RDP vulnerabilities) to the victim system, and attempt to access an Active Directory domain database (NTDS.dit) [T1003.003].
In one case, FBI observed BianLian actors use a portable executable version of an Impacket tool (secretsdump.py) to move laterally to a domain controller and harvest credential hashes from it. Note: Impacket is a Python toolkit for programmatically constructing and manipulating network protocols. Through the Command Shell, an Impacket user with credentials can run commands on a remote device using the Windows management protocols required to support an enterprise network. Threat actors can run portable executable files on victim systems using local user rights, assuming the executable is not blocked by an application allowlist or antivirus solution.
See Appendix: Windows PowerShell and Command Shell Activity for additional information.
Persistence and Lateral Movement
BianLian group actors use PsExec and RDP with valid accounts for lateral movement [T1021.001]. Prior to using RDP, BianLian actors used Command Shell and native Windows tools to add user accounts to the local Remote Desktop Users group, modified the added account’s password, and modified Windows firewall rules to allow incoming RDP traffic [T1562.004]. See Appendix: Windows PowerShell and Command Shell Activity for additional information.
In one case, FBI found a forensic artifact (exp.exe) on a compromised system that likely exploits the Netlogon vulnerability (CVE-2020-1472) and connects to a domain controller.
Collection
FBI observed BianLian group actors using malware (system.exe) that enumerates registry [T1012] and files [T1083] and copies clipboard data from users [T1115].
Exfiltration and Impact
BianLian group actors search for sensitive files using PowerShell scripts (See Appendix: Windows PowerShell and Command Shell Activity) and exfiltrate them for data extortion. Prior to January 2023, BianLian actors encrypted files [T1486] after exfiltration for double extortion.
BianLian group uses File Transfer Protocol (FTP) [T1048] and Rclone, a tool used to sync files to cloud storage, to exfiltrate data [T1537]. FBI observed BianLian group actors install Rclone and other files in generic and typically unchecked folders such as programdatavmware and music folders. ACSC observed BianLian group actors use Mega file-sharing service to exfiltrate victim data [T1567.002].
BianLian’s encryptor (encryptor.exe) modified all encrypted files to have the .bianlian extension. The encryptor created a ransom note, Look at this instruction.txt, in each affected directory (see Figure 1 for an example ransom note.) According to the ransom note, BianLian group specifically looked for, encrypted, and exfiltrated financial, client, business, technical, and personal files.
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If a victim refuses to pay the ransom demand, BianLian group threatens to publish exfiltrated data to a leak site maintained on the Tor network. The ransom note provides the Tox ID A4B3B0845DA242A64BF17E0DB4278EDF85855739667D3E2AE8B89D5439015F07E81D12D767FC, which does not vary across victims. The Tox ID directs the victim organization to a Tox chat via https://qtox.github[.]io and includes an alternative contact email address (swikipedia@onionmail[.]org or xxx@mail2tor[.]com). The email address is also the same address listed on the group’s Tor site under the contact information section. Each victim company is assigned a unique identifier included in the ransom note. BianLian group receives payments in unique cryptocurrency wallets for each victim company.
BianLian group engages in additional techniques to pressure the victim into paying the ransom; for example, printing the ransom note to printers on the compromised network. Employees of victim companies also reported receiving threatening telephone calls from individuals associated with BianLian group.
Indicators of Compromise (IOC)
See Table 1 for IOCs obtained from FBI investigations as of March 2023.
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Name |
SHA-256 Hash |
Description |
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7b15f570a23a5c5ce8ff942da60834a9d0549ea3ea9f34f900a09331325df893 |
Malware associated with BianLian intrusions, which is an example of a possible backdoor developed by BianLian group. |
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1fd07b8d1728e416f897bef4f1471126f9b18ef108eb952f4b75050da22e8e43 |
Example of a BianLian encryptor. |
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0c1eb11de3a533689267ba075e49d93d55308525c04d6aff0d2c54d1f52f5500 |
Possible NetLogon vulnerability (CVE-2020-1472) exploitation. |
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40126ae71b857dd22db39611c25d3d5dd0e60316b72830e930fba9baf23973ce |
Enumerates registry and files. Reads clipboard data. |
MITRE ATT&CK Techniques
See Table 2 for all referenced threat actor tactics and techniques in this advisory.
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Technique Title |
ID |
Use |
|---|---|---|
Resource Development |
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Develop Capabilities: Malware |
BianLian group actors developed a custom backdoor used in their intrusions. |
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Initial Access |
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External Remote Services |
BianLian group actors used RDP with valid accounts as a means of gaining initial access and for lateral movement. |
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Phishing |
BianLian group actors used phishing to obtain valid user credentials for initial access. |
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Valid Accounts |
BianLian group actors used RDP with valid accounts as a means of gaining initial access and for lateral movement. |
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Execution |
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Command and Scripting Interpreter: PowerShell |
BianLian group actors used PowerShell to disable AMSI on Windows. See Appendix: Windows PowerShell and Command Shell Activity for additional information. |
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Command and Scripting Interpreter: Windows Command Shell |
BianLian group actors used Windows Command Shell to disable antivirus tools, for discovery, and to execute their tools on victim networks. See Appendix: Windows PowerShell and Command Shell Activity for additional information. |
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Scheduled Task/Job: Scheduled Task |
BianLian group actors used a Scheduled Task run as SYSTEM (the highest privilege Windows accounts) to execute a Dynamic Link Library (DLL) file daily. See Appendix: Windows PowerShell and Command Shell Activity for additional information. |
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Persistence |
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Account Manipulation |
BianLian group actors changed the password of an account they created. BianLian actors modified the password of an account they added to the local Remote Desktop Users group. |
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Create Account: Local Account |
BianLian group actors created/activated a local administrator account. BianLian group actors used net.exe to add a user account to the local Remote Desktop Users group. (See Appendix: Windows PowerShell and Command Shell Activity for more information.) |
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Defense Evasion |
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Modify Registry |
BianLian group actors modified the registry to disable user authentication for RDP connections, allow a user to receive help from Remote Assistance, and disable tamper protection for Sophos SAVEnabled, SEDEenabled, and SAVService services, which enables them to uninstall these services. |
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Impair Defenses: Disable or Modify Tools |
BianLian group actors disabled Windows defender, AMSI, and Sophos SAVEnabled and SEDEenabled tamper protection services. See Appendix: Windows PowerShell and Command Shell Activity for additional information. |
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Impair Defenses: Disable or Modify System Firewall |
BianLian group actors added modified firewalls to allow RDP traffic by adding new rules to the Windows firewall that allow incoming RDP traffic and enable a pre-existing Windows firewall rule group named Remote Desktop. |
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Credential Access |
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OS Credential Dumping: LSASS Memory |
BianLian group actors accessed credential material stored in the process memory of the LSASS. See Appendix: Windows PowerShell and Command Shell Activity for additional information. |
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OS Credential Dumping: NTDS |
BianLian group actors attempted to access or create a copy of the Active Directory domain database in order to steal credential information and to obtain other information about domain members such as devices, users, and access rights. |
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Unsecured Credentials: Credentials In Files |
BianLian group actors searched local file systems and remote file shares for files containing insecurely stored credentials. |
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Discovery |
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Account Discovery: Domain Account |
BianLian group actors queried the domain controller to identify accounts in the Domain Admins and Domain Computers groups. This information can help adversaries determine which domain accounts exist to aid in follow-on activity. |
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Domain Trust Discovery |
BianLian group actors used PingCastle to enumerate the AD and map trust relationships. BianLian group actors retrieved a list of domain trust relationships used to identify lateral movement opportunities in Windows multi-domain/forest environments. |
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File and Directory Discovery |
BianLian group used malware (system.exe) that enumerates files. |
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Network Service Discovery |
BianLian actors used Advanced Port Scanner and SoftPerfect Network Scanner to ping computers, scan ports, and identify program versions running on ports. |
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Network Share Discovery |
BianLian actors used SoftPerfect Network Scanner, which can discover shared folders. BianLian group actors used SharpShares to enumerate accessible network shares in a domain. |
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Permission Groups Discovery: Domain Groups |
BianLian group actors queried the domain controller to identify groups. |
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Query Registry |
BianLian group used malware (system.exe) that enumerates registry. |
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Remote System Discovery |
BianLian group actors attempted to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for lateral movement. BianLian group actors retrieved a list of domain controllers. |
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System Owner User Discovery |
BianLian group actors queried currently logged-in users on a machine. |
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Lateral Movement |
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Remote Services: Remote Desktop Protocol |
BianLian group actors used RDP with valid accounts for lateral movement. |
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Collection |
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Clipboard Data |
BianLian group actors’ malware collects data stored in the clipboard from users copying information within or between applications. |
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Command and Control |
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Ingress Tool Transfer |
BianLian group actors transferred tools or other files from an external system into a compromised environment. |
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Remote Access Software |
BianLian group actors used legitimate desktop support and remote access software, such as TeamViewer, Atera, and SplashTop, to establish an interactive command and control channel to target systems within networks. |
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Exfiltration |
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Transfer Data to Cloud Account |
BianLian group actors used Rclone to exfiltrate data to a cloud account they control on the same service to avoid typical file transfers/downloads and network-based exfiltration detection. |
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Exfiltration Over Alternative Protocol |
BianLian group actors exfiltrated data via FTP. |
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Exfiltration Over Web Service: Exfiltration to Cloud Storage |
BianLian group actors exfiltrated data via Mega public file-sharing service. |
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Impact |
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Data Encrypted for Impact |
BianLian group actors encrypted data on target systems. |
Mitigations
FBI, CISA, and ACSC recommend organizations implement the mitigations below to improve your organization’s cybersecurity posture on the basis of the threat actors’ activity. These mitigations align with the Cross-Sector Cybersecurity Performance Goals (CPGs) developed by CISA and the National Institute of Standards and Technology (NIST). The CPGs provide a minimum set of practices and protections that CISA and NIST recommend all organizations implement. CISA and NIST based the CPGs on existing cybersecurity frameworks and guidance to protect against the most common and impactful threats and TTPs. Visit CISA’s Cross-Sector Cybersecurity Performance Goals for more information on the CPGs, including additional recommended baseline protections.
- Reduce threat of malicious actors using remote access tools by:
- Auditing remote access tools on your network to identify currently used and/or authorized software.
- Reviewing logs for execution of remote access software to detect abnormal use of programs running as a portable executable [CPG 2.T].
- Using security software to detect instances of remote access software only being loaded in memory.
- Requiring authorized remote access solutions only be used from within your network over approved remote access solutions, such as virtual private networks (VPNs) or virtual desktop interfaces (VDIs).
- Blocking both inbound and outbound connections on common remote access software ports and protocols at the network perimeter.
- Implement application controls to manage and control execution of software, including allowlisting remote access programs.
- Application controls should prevent installation and execution of portable versions of unauthorized remote access and other software. A properly configured application allowlisting solution will block any unlisted application execution. Allowlisting is important because antivirus solutions may fail to detect the execution of malicious portable executables when the files use any combination of compression, encryption, or obfuscation.
See NSA Cybersecurity Information sheet Enforce Signed Software Execution Policies for additional guidance.
- Strictly limit the use of RDP and other remote desktop services. If RDP is necessary, rigorously apply best practices, for example [CPG 2.W]:
- Audit the network for systems using RDP.
- Close unused RDP ports.
- Enforce account lockouts after a specified number of attempts.
- Apply phishing-resistant multifactor authentication (MFA).
- Log RDP login attempts.
- Disable command-line and scripting activities and permissions [CPG 2.N].
- Restrict the use of PowerShell, using Group Policy, and only grant to specific users on a case-by-case basis. Typically, only those users or administrators who manage the network or Windows operating systems (OSs) should be permitted to use PowerShell [CPG 2.E].
- Update Windows PowerShell or PowerShell Core to the latest version and uninstall all earlier PowerShell versions. Logs from Windows PowerShell prior to version 5.0 are either non-existent or do not record enough detail to aid in enterprise monitoring and incident response activities [CPG 1.E, 2.S, 2.T].
- Enable enhanced PowerShell logging [CPG 2.T, 2.U].
- PowerShell logs contain valuable data, including historical OS and registry interaction and possible TTPs of a threat actor’s PowerShell use.
- Ensure PowerShell instances, using the latest version, have module, script block, and transcription logging enabled (enhanced logging).
- The two logs that record PowerShell activity are the PowerShell Windows Event Log and the PowerShell Operational Log. FBI and CISA recommend turning on these two Windows Event Logs with a retention period of at least 180 days. These logs should be checked on a regular basis to confirm whether the log data has been deleted or logging has been turned off. Set the storage size permitted for both logs to as large as possible.
- Configure the Windows Registry to require User Account Control (UAC) approval for any PsExec operations requiring administrator privileges to reduce the risk of lateral movement by PsExec.
- Review domain controllers, servers, workstations, and active directories for new and/or unrecognized accounts [CPG 4.C].
- Audit user accounts with administrative privileges and configure access controls according to the principle of least privilege [CPG 2.E].
- Reduce the threat of credential compromise via the following:
- Place domain admin accounts in the protected users’ group to prevent caching of password hashes locally.
- Implement Credential Guard for Windows 10 and Server 2016 (Refer to Microsoft: Manage Windows Defender Credential Guard for more information). For Windows Server 2012R2, enable Protected Process Light for Local Security Authority (LSA).
- Refrain from storing plaintext credentials in scripts.
- Implement time-based access for accounts set at the admin level and higher [CPG 2.A, 2.E]. For example, the Just-in-Time (JIT) access method provisions privileged access when needed and can support enforcement of the principle of least privilege (as well as the Zero Trust model). This is a process where a network-wide policy is set in place to automatically disable admin accounts at the Active Directory (AD) level when the account is not in direct need. Individual users may submit their requests through an automated process that grants them access to a specified system for a set timeframe when they need to support the completion of a certain task.
In addition, FBI, CISA, and ACSC recommend network defenders apply the following mitigations to limit potential adversarial use of common system and network discovery techniques and to reduce the impact and risk of compromise by ransomware or data extortion actors:
- Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, and secure location (e.g., hard drive, storage device, or the cloud).
- Maintain offline backups of data, and regularly maintain backup and restoration (daily or weekly at minimum). By instituting this practice, an organization minimizes the impact of disruption to business practices as they will not be as severe and/or only have irretrievable data [CPG 2.R]. ACSC recommends organizations follow the 3-2-1 backup strategy in which organizations have three copies of data (one copy of production data and two backup copies) on two different media such as disk and tape, with one copy kept off-site for disaster recovery.
- Require all accounts with password logins (e.g., service account, admin accounts, and domain admin accounts) to comply with National Institute for Standards and Technology (NIST) standards for developing and managing password policies.
- Use longer passwords consisting of at least 15 characters [CPG 2.B].
- Store passwords in hashed format using industry-recognized password managers.
- Add password user “salts” to shared login credentials.
- Avoid reusing passwords [CPG 2.C].
- Implement multiple failed login attempt account lockouts [CPG 2.G].
- Disable password “hints”.
- Refrain from requiring password changes more frequently than once per year.
Note: NIST guidance suggests favoring longer passwords instead of requiring regular and frequent password resets. Frequent password resets are more likely to result in users developing password “patterns” cyber criminals can easily decipher. - Require administrator credentials to install software.
- Require phishing-resistant multifactor authentication for all services to the extent possible, particularly for webmail, virtual private networks, and accounts that access critical systems [CPG 2.H].
- Keep all operating systems, software, and firmware up to date. Timely patching is one of the most efficient and cost-effective steps an organization can take to minimize its exposure to cybersecurity threats. Organizations should patch vulnerable software and hardware systems within 24 to 48 hours from vulnerability disclosure. Prioritize patching known exploited vulnerabilities in internet-facing systems [CPG 1.E].
- Segment networks to prevent the spread of ransomware. Network segmentation can help prevent the spread of ransomware by controlling traffic flows between—and access to—various subnetworks, restricting further lateral movement [CPG 2.F].
- Identify, detect, and investigate abnormal activity and potential traversal of the indicated ransomware with a networking monitoring tool. To aid in detecting ransomware, implement a tool that logs and reports all network traffic, including lateral movement activity on a network. Endpoint detection and response (EDR) tools are particularly useful for detecting lateral connections, as they have insight into common and uncommon network connections for each host [CPG 3.A].
- Install, regularly update, and enable real time detection for antivirus software on all hosts.
- Disable unused ports [CPG 2.V].
- Consider adding an email banner to emails received from outside your organization [CPG 2.M].
- Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure [CPG 2.K, 2.L, 2.R].
Validate Security Controls
In addition to applying mitigations, FBI, CISA, and ACSC recommend exercising, testing, and validating your organization's security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. FBI, CISA, and ACSC recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.
To get started:
- Select an ATT&CK technique described in this advisory (see Table 2).
- Align your security technologies against the technique.
- Test your technologies against the technique.
- Analyze your detection and prevention technologies’ performance.
- Repeat the process for all security technologies to obtain a set of comprehensive performance data.
- Tune your security program, including people, processes, and technologies, based on the data generated by this process.
FBI, CISA, and ACSC recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.
RESOURCES
- Stopransomware.gov, a whole-of-government approach with one central location for U.S. ransomware resources and alerts.
- cyber.gov.au for the Australian Government’s central location to report cyber incidents, including ransomware, and to see advice and alerts. The site also provides ransomware advisories for businesses and organizations to help mitigate cyber threats.
- CISA-Multi-State Information Sharing and Analysis Center (MS-ISAC) Joint Ransomware Guide for guidance on mitigating and responding to a ransomware attack
- For no-cost cyber hygiene services for U.S. organizations, Cyber Hygiene Services and Ransomware Readiness Assessment.
Reporting
The FBI is seeking any information that can be shared, including boundary logs showing communication to and from foreign IP addresses, a sample ransom note, communications with BianLian actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file. The FBI and CISA do not encourage paying ransom, as payment does not guarantee victim files will be recovered. Furthermore, payment may also embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. Regardless of whether you or your organization have decided to pay the ransom, the FBI and CISA urge you to promptly report ransomware incidents to a local FBI Field Office or CISA at cisa.gov/report. Australian organizations that have been impacted or require assistance in regard to a ransomware incident can contact ACSC via 1300 CYBER1 (1300 292 371) or by submitting a report cyber.gov.au.
Acknowledgements
Microsoft and Sophos contributed to this advisory.
APPENDIX: WINDOWS PowerSHell and COMMAND SHELL ACTIVITY
Through FBI investigations as of March 2023, FBI has observed BianLian actors use the commands in Table 3. ACSC has observed BianLian actors use some of the same commands.
|
Command |
Use |
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[Ref].Assembly.GetType(‘System.Management.Automation.AmsiUtils’).GetField(‘amsiInitFailed’,’NonPublic,* Static’).SetValue($null,$true) |
Disables the AMSI on Windows. AMSI is a built-in feature on Windows 10 and newer that provides an interface for anti-malware scanners to inspect scripts prior to execution. When AMSI is disabled, malicious scripts may bypass antivirus solutions and execute undetected. |
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cmd.exe /Q /c for /f “tokens=1,2 delims= “ ^%A in (‘”tasklist /fi “Imagename eq lsass.exe” | find “lsass””’) do rundll32.exe C:windowsSystem32comsvcs.dll, MiniDump ^%B WindowsTemp |
Creates a memory dump lsass.exe process and saves it as a CSV filehttps://attack.mitre.org/versions/v12/techniques/T1003/001/. BianLian actors used it to harvest credentials from lsass.exe. |
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cmd.exe /Q /c net user |
Activates the local Administrator account. |
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cmd.exe /Q /c net user " |
Changes the password of the newly activated local Administrator account. |
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cmd.exe /Q /c quser 1> \127.0.0.1C$WindowsTemp |
Executes quser.exe to query the currently logged-in users on a machine. The command is provided arguments to run quietly and exit upon completion, and the output is directed to the WindowsTemp directory. |
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dism.exe /online /Disable-Feature /FeatureName:Windows-Defender /Remove /NoRestart |
Using the Deployment Image Servicing and Management (DISM) executable file, removes the Windows Defender feature. |
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dump.exe -no-pass -just-dc user.local/ |
Executes secretsdump.py, a Portable Executable version of an Impacket tool. Used to dump password hashes from domain controllers. |
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exp.exe -n |
Possibly attempted exploitation of the NetLogon vulnerability (CVE-2020-1472). |
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findstr /spin "password" *.* >C:UserstrainingMusic |
Searches for the string password in all files in the current directory and its subdirectories and puts the output to a file. |
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ldap.exe -u user |
Connects to the organization’s Lightweight Directory Access Protocol (LDAP) server. |
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logoff |
Logs off the current user from a Windows session. Can be used to log off multiple users at once. |
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mstsc |
Launches Microsoft Remote Desktop Connection client application in Windows. |
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net group /domain |
Retrieves a list of all groups from the domain controller. |
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net group 'Domain Admins' /domain |
Queries the domain controller to retrieve a list of all accounts from Domain Admins group. |
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net group 'Domain Computers' /domain |
Queries the domain controller to retrieve a list of all accounts from Domain Computers group. |
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net user /domain |
Queries the domain controller to retrieve a list of all users in the domain. |
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net.exe localgroup "Remote Desktop Users" |
Adds a user account to the local Remote Desktop Users group. |
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net.exe user |
Modifies the password for the specified account. |
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netsh.exe advfirewall firewall add rule "name=allow RemoteDesktop" dir=in * protocol=TCP localport= |
Adds a new rule to the Windows firewall that allows incoming RDP traffic. |
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netsh.exe advfirewall firewall set rule "group=remote desktop" new enable=Yes |
Enables the pre-existing Windows firewall rule group named Remote Desktop. This rule group allows incoming RDP traffic. |
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nltest /dclist |
Retrieves a list of domain controllers. |
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nltest /domain_trusts |
Retrieves a list of domain trusts. |
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ping.exe -4 -n 1 * |
Sends a single ICMP echo request packet to all devices on the local network using the IPv4 protocol. The output of the command will show if the device is reachable or not. |
|
quser; ([adsisearcher]"(ObjectClass=computer)").FindAll().count;([adsisearcher]"(ObjectClass=user)").FindAll().count;[Security.Principal.WindowsIdentity]::GetCurrent() | select name;net user "$env:USERNAME" /domain; (Get-WmiObject -class Win32_OperatingSystem).Caption; Get-WmiObject -Namespace rootcimv2 -Class Win32_ComputerSystem; net group "domain admins" /domain; nltest /dclist:; nltest /DOMAIN_TRUSTS |
Lists the current Windows identity for the logged-in user and displays the user's name. Uses the Active Directory Services Interface (ADSI) to search for all computer and user objects in the domain and returns counts of the quantities found. Lists information about the current user account from the domain, such as the user's name, description, and group memberships. Lists information about the operating system installed on the local computer. Lists information about the "Domain Admins" group from the domain. Lists all domain controllers in the domain. Displays information about domain trusts. |
|
reg.exe add "HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlTerminal * ServerWinStationsRDP-Tcp" /v UserAuthentication /t REG_DWORD /d 0 /f |
Adds/overwrites a new Registry value to disable user authentication for RDP connections. |
|
reg.exe add "HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlTerminal Server" /* v fAllowToGetHelp /t REG_DWORD /d 1 /f |
Adds/overwrites a new Registry value to allow a user to receive help from Remote Assistance. |
|
reg.exe add "HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesSophos Endpoint * DefenseTamperProtectionConfig" /t REG_DWORD /v SAVEnabled /d 0 /f |
Adds/overwrites a new Registry value to disable tamper protection for Sophos antivirus named SAVEnabled. |
|
reg.exe add "HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesSophos Endpoint * DefenseTamperProtectionConfig" /t REG_DWORD /v SEDEnabled /d 0 /f |
Adds/overwrites a new Registry value to disable tamper protection for Sophos antivirus named SEDEnabled. |
|
reg.exe ADD * HKEY_LOCAL_MACHINESOFTWAREWOW6432NodeSophosSAVServiceTamperProtection /t REG_DWORD /v Enabled /d 0 /f |
Adds/overwrites a new registry value to disable tamper protection for a Sophos antivirus service called SAVService. |
|
reg.exe copy hklmsystemCurrentControlSetservicestvnserver * hklmsystemCurrentControlSetcontrolsafebootnetworktvnserver /s /f |
Copies the configuration settings for the tvnserver service to a new location in the registry that will be used when the computer boots into Safe Mode with Networking. This allows the service to run with the same settings in Safe Mode as it does in normal mode. |
|
s.exe /threads:50 /ldap:all /verbose /outfile:c:users |
Executes SharpShares. |
|
schtasks.exe /RU SYSTEM /create /sc ONCE / |
Creates a Scheduled Task run as SYSTEM at 0443 AM. When the task is run, cmd.exe uses crundll32.exe to run the DLL file netsh.dll. (It is likely that netsh.dll is a malware file and not associated with netsh.) |
|
start-process PowerShell.exe -arg C:UsersPublicMusic |
Executes a PowerShell script, while keeping the PowerShell window hidden from the user. |
Disclaimer
The information in this report is being provided “as is” for informational purposes only. FBI, CISA, and ACSC do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by FBI, CISA, or ACSC.
Summary
This joint Cybersecurity Advisory (CSA) provides the top Common Vulnerabilities and Exposures (CVEs) used since 2020 by People’s Republic of China (PRC) state-sponsored cyber actors as assessed by the National Security Agency (NSA), Cybersecurity and Infrastructure Security Agency (CISA), and Federal Bureau of Investigation (FBI). PRC state-sponsored cyber actors continue to exploit known vulnerabilities to actively target U.S. and allied networks as well as software and hardware companies to steal intellectual property and develop access into sensitive networks.
This joint CSA builds on previous NSA, CISA, and FBI reporting to inform federal and state, local, tribal and territorial (SLTT) government; critical infrastructure, including the Defense Industrial Base Sector; and private sector organizations about notable trends and persistent tactics, techniques, and procedures (TTPs).
NSA, CISA, and FBI urge U.S. and allied governments, critical infrastructure, and private sector organizations to apply the recommendations listed in the Mitigations section and Appendix A to increase their defensive posture and reduce the threat of compromise from PRC state-sponsored malicious cyber actors.
For more information on PRC state-sponsored malicious cyber activity, see CISA’s China Cyber Threat Overview and Advisories webpage, FBI’s Industry Alerts, and NSA’s Cybersecurity Advisories & Guidance.
Download the PDF version of this report: pdf, 409 KB
Technical Details
NSA, CISA, and FBI continue to assess PRC state-sponsored cyber activities as being one of the largest and most dynamic threats to U.S. government and civilian networks. PRC state-sponsored cyber actors continue to target government and critical infrastructure networks with an increasing array of new and adaptive techniques—some of which pose a significant risk to Information Technology Sector organizations (including telecommunications providers), Defense Industrial Base (DIB) Sector organizations, and other critical infrastructure organizations.
PRC state-sponsored cyber actors continue to exploit known vulnerabilities and use publicly available tools to target networks of interest. NSA, CISA, and FBI assess PRC state-sponsored cyber actors have actively targeted U.S. and allied networks as well as software and hardware companies to steal intellectual property and develop access into sensitive networks. See Table 1 for the top used CVEs.
Table I: Top CVEs most used by Chinese state-sponsored cyber actors since 2020
|
Vendor |
CVE |
Vulnerability Type |
|
Apache Log4j |
CVE-2021-44228 |
Remote Code Execution |
|
Pulse Connect Secure |
CVE-2019-11510 |
Arbitrary File Read |
|
GitLab CE/EE |
CVE-2021-22205 |
Remote Code Execution |
|
Atlassian |
CVE-2022-26134 |
Remote Code Execution |
|
Microsoft Exchange |
CVE-2021-26855 |
Remote Code Execution |
|
F5 Big-IP |
CVE-2020-5902 |
Remote Code Execution |
|
VMware vCenter Server |
CVE-2021-22005 |
Arbitrary File Upload |
|
Citrix ADC |
CVE-2019-19781 |
Path Traversal |
|
Cisco Hyperflex |
CVE-2021-1497 |
Command Line Execution |
|
Buffalo WSR |
CVE-2021-20090 |
Relative Path Traversal |
|
Atlassian Confluence Server and Data Center |
CVE-2021-26084 |
Remote Code Execution |
|
Hikvision Webserver |
CVE-2021-36260 |
Command Injection |
|
Sitecore XP |
CVE-2021-42237 |
Remote Code Execution |
|
F5 Big-IP |
CVE-2022-1388 |
Remote Code Execution |
|
Apache |
CVE-2022-24112 |
Authentication Bypass by Spoofing |
|
ZOHO |
CVE-2021-40539 |
Remote Code Execution |
|
Microsoft |
CVE-2021-26857 |
Remote Code Execution |
|
Microsoft |
CVE-2021-26858 |
Remote Code Execution |
|
Microsoft |
CVE-2021-27065 |
Remote Code Execution |
|
Apache HTTP Server |
CVE-2021-41773 |
Path Traversal |
These state-sponsored actors continue to use virtual private networks (VPNs) to obfuscate their activities and target web-facing applications to establish initial access. Many of the CVEs indicated in Table 1 allow the actors to surreptitiously gain unauthorized access into sensitive networks, after which they seek to establish persistence and move laterally to other internally connected networks. For additional information on PRC state-sponsored cyber actors targeting network devices, please see People’s Republic of China State-Sponsored Cyber Actors Exploit Network Providers and Devices.
Mitigations
NSA, CISA, and FBI urge organizations to apply the recommendations below and those listed in Appendix A.
- Update and patch systems as soon as possible. Prioritize patching vulnerabilities identified in this CSA and other known exploited vulnerabilities.
- Utilize phishing-resistant multi-factor authentication whenever possible. Require all accounts with password logins to have strong, unique passwords, and change passwords immediately if there are indications that a password may have been compromised.
- Block obsolete or unused protocols at the network edge.
- Upgrade or replace end-of-life devices.
- Move toward the Zero Trust security model.
- Enable robust logging of Internet-facing systems and monitor the logs for anomalous activity.
Appendix A
Table II: Apache CVE-2021-44228
|
Apache CVE-2021-44228 CVSS 3.0: 10 (Critical) |
|
Vulnerability Description Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, and 2.3.1) JNDI features used in configuration, log messages, and parameters do not protect against malicious actor controlled LDAP and other JNDI related endpoints. A malicious actor who can control log messages or log message parameters could execute arbitrary code loaded from LDAP servers when message lookup substitution is enabled. From log4j 2.15.0, this behavior has been disabled by default. From version 2.16.0 (along with 2.12.2, 2.12.3, and 2.3.1), this functionality has been completely removed. Note that this vulnerability is specific to log4j-core and does not affect log4net, log4cxx, or other Apache Logging Services projects. |
|
Recommended Mitigations
|
|
Detection Methods |
|
Vulnerable Technologies and Versions There are numerous vulnerable technologies and versions associated with CVE-2021-44228. For a full list, check https://nvd.nist.gov/vuln/detail/CVE-2021-44228. |
Table III: Pulse CVE-2019-11510
|
Pulse CVE-2019-11510 CVSS 3.0: 10 (Critical) |
|
Vulnerability Description This vulnerability has been modified since it was last analyzed by NVD. It is awaiting reanalysis, which may result in further changes to the information provided. In Pulse Secure Pulse Connect Secure (PCS) 8.2 before 8.2R12.1, 8.3 before 8.3R7.1, and 9.0 before 9.0R3.4, an unauthenticated remote malicious actor could send a specially crafted URI to perform an arbitrary file reading vulnerability. |
|
Recommended Mitigations
|
|
Detection Methods
|
|
Vulnerable Technologies and Versions Pulse Connect Secure (PCS) 8.2 before 8.2R12.1, 8.3 before 8.3R7.1, and 9.0 before 9.0R3.4 |
Table IV: GitLab CVE-2021-22205
|
GitLab CVE-2021-22205 CVSS 3.0: 10 (Critical) |
|
Vulnerability Description An issue has been discovered in GitLab CE/EE affecting all versions starting from 11.9. GitLab was not properly validating image files passed to a file parser, which resulted in a remote command execution. |
|
Recommended Mitigations
|
|
Detection Methods
|
|
Vulnerable Technologies and Versions Gitlab CE/EE. |
Table V: Atlassian CVE-2022-26134
|
Atlassian CVE-2022-26134 CVSS 3.0: 9.8 (Critical) |
|
Vulnerability Description In affected versions of Confluence Server and Data Center, an OGNL injection vulnerability exists that could allow an unauthenticated malicious actor to execute arbitrary code on a Confluence Server or Data Center instance. The affected versions are from 1.3.0 before 7.4.17, 7.13.0 before 7.13.7, 7.14.0 before 7.14.3, 7.15.0 before 7.15.2, 7.16.0 before 7.16.4, 7.17.0 before 7.17.4, and 7.18.0 before 7.18.1. |
|
Recommended Mitigations
|
|
Detection Methods N/A |
|
Vulnerable Technologies and Versions All supported versions of Confluence Server and Data Center Confluence Server and Data Center versions after 1.3.0 |
Table VI: Microsoft CVE-2021-26855
|
Microsoft CVE-2021-26855 CVSS 3.0: 9.8 (Critical) |
|
Vulnerability Description Microsoft has released security updates for Windows Exchange Server. To exploit these vulnerabilities, an authenticated malicious actor could send malicious requests to an affected server. A malicious actor who successfully exploited these vulnerabilities would execute arbitrary code and compromise the affected systems. If successfully exploited, these vulnerabilities could allow an adversary to obtain access to sensitive information, bypass security restrictions, cause a denial of service conditions, and/or perform unauthorized actions on the affected Exchange server, which could aid in further malicious activity. |
|
Recommended Mitigations
|
|
Detection Methods
|
|
Vulnerable Technologies and Versions Microsoft Exchange 2013, 2016, and 2019. |
Table VII: F5 CVE-2020-5902
|
F5 CVE-2020-5902 CVSS 3.0: 9.8 (Critical) |
|
Vulnerability Description In BIG-IP versions 15.0.0-15.1.0.3, 14.1.0-14.1.2.5, 13.1.0-13.1.3.3, 12.1.0-12.1.5.1, and 11.6.1-11.6.5.1, the Traffic Management User Interface (TMUI), also referred to as the Configuration utility, has a Remote Code Execution (RCE) vulnerability in undisclosed pages. |
|
Recommended Mitigations
|
|
Detection Methods
|
|
Vulnerable Technologies and Versions F5 Big-IP Access Policy Manager F5 Big-IP Advanced Firewall Manager F5 Big-IP Advanced Web Application Firewall F5 Big-IP Analytics F5 Big-IP Application Acceleration Manager F5 Big-IP Application Security Manager F5 Big-IP Ddos Hybrid Defender F5 Big-IP Domain Name System (DNS) F5 Big-IP Fraud Protection Service (FPS) F5 Big-IP Global Traffic Manager (GTM) F5 Big-IP Link Controller F5 Networks Big-IP Local Traffic Manager (LTM) F5 Big-IP Policy Enforcement Manager (PEM) F5 SSL Orchestrator |
|
References https://support.f5.com/csp/article/K00091341 https://support.f5.com/csp/article/K07051153 https://support.f5.com/csp/article/K20346072 https://support.f5.com/csp/article/K31301245 https://support.f5.com/csp/article/K33023560 https://support.f5.com/csp/article/K43638305 |
Table VIII: VMware CVE-2021-22005
|
VMware CVE-2021-22005 CVSS 3.0: 9.8 (Critical) |
|
Vulnerability Description The vCenter Server contains an arbitrary file upload vulnerability in the Analytics service. A malicious actor with network access to port 443 on vCenter Server may exploit this issue to execute code on vCenter Server by uploading a specially crafted file. |
|
Recommended Mitigations
|
|
Detection Methods N/A |
|
Vulnerable Technologies and Versions VMware Cloud Foundation VMware VCenter Server |
Table IX: Citrix CVE-2019-19781
|
Citrix CVE-2019-19781 CVSS 3.0: 9.8 (Critical) |
|
Vulnerability Description This vulnerability has been modified since it was last analyzed by NVD. It is awaiting reanalysis, which may result in further changes to the information provided. An issue was discovered in Citrix Application Delivery Controller (ADC) and Gateway 10.5, 11.1, 12.0, 12.1, and 13.0. They allow Directory Traversal. |
|
Recommended Mitigations
|
|
Detection Methods N/A |
|
Vulnerable Technologies and Versions Citrix ADC, Gateway, and SD-WAN WANOP |
Table X: Cisco CVE-2021-1497
|
Cisco CVE-2021-1497 CVSS 3.0: 9.8 (Critical) |
|
Vulnerability Description Multiple vulnerabilities in the web-based management interface of Cisco HyperFlex HX could allow an unauthenticated, remote malicious actor to perform a command injection against an affected device. For more information about these vulnerabilities, see the Technical details section of this advisory. |
|
Recommended Mitigations
|
|
Detection Methods
|
|
Vulnerable Technologies and Versions Cisco Hyperflex Hx Data Platform 4.0(2A) |
Table XI: Buffalo CVE-2021-20090
|
Buffalo CVE-2021-20090 CVSS 3.0: 9.8 (Critical) |
|
Vulnerability Description A path traversal vulnerability in the web interfaces of Buffalo WSR-2533DHPL2 firmware version |
|
Recommended Mitigations
|
|
Detection Methods
|
|
Vulnerable Technologies and Versions Buffalo Wsr-2533Dhpl2-Bk Firmware Buffalo Wsr-2533Dhp3-Bk Firmware |
Table XII: Atlassian CVE-2021-26084
|
Atlassian CVE-2021-26084 CVSS 3.0: 9.8 (Critical) |
|
Vulnerability Description In affected versions of Confluence Server and Data Center, an OGNL injection vulnerability exists that would allow an unauthenticated malicious actor to execute arbitrary code on a Confluence Server or Data Center instance. The affected versions are before version 6.13.23 and from version 6.14.0 before 7.4.11, version 7.5.0 before 7.11.6, and version 7.12.0 before 7.12.5. |
|
Recommended Mitigations
|
|
Detection Methods N/A |
|
Vulnerable Technologies and Versions Atlassian Confluence Atlassian Confluence Server Atlassian Data Center Atlassian Jira Data Center |
Table XIII: Hikvision CVE-2021-36260
|
Hikvision CVE-2021-36260 CVSS 3.0: 9.8 (Critical) |
|
Vulnerability Description This vulnerability has been modified since it was last analyzed by NVD. It is awaiting reanalysis, which may result in further changes to the information provided. A command injection vulnerability exists in the web server of some Hikvision products. Due to the insufficient input validation, a malicious actor can exploit the vulnerability to launch a command injection by sending some messages with malicious commands. |
|
Recommended Mitigations
|
|
Detection Methods N/A |
|
Vulnerable Technologies and Versions Various Hikvision Firmware to include Ds, Ids, and Ptz |
|
References |
Table XIV: Sitecore CVE-2021-42237
|
Sitecore CVE-2021-42237 CVSS 3.0: 9.8 (Critical) |
|
Vulnerability Description Sitecore XP 7.5 Initial Release to Sitecore XP 8.2 Update-7 is vulnerable to an insecure deserialization attack where it is possible to achieve remote command execution on the machine. No authentication or special configuration is required to exploit this vulnerability. |
|
Recommended Mitigations
|
|
Detection Methods
|
|
Vulnerable Technologies and Versions Sitecore Experience Platform 7.5, 7.5 Update 1, and 7.5 Update 2 Sitecore Experience Platform 8.0, 8.0 Service Pack 1, and 8.0 Update 1-Update 7 Sitecore Experience Platform 8.0 Service Pack 1 Sitecore Experience Platform 8.1, and Update 1-Update 3 Sitecore Experience Platform 8.2, and Update 1-Update 7 |
Table XV: F5 CVE-2022-1388
|
F5 CVE-2022-1388 CVSS 3.0: 9.8 (Critical) |
|
Vulnerability Description This vulnerability has been modified since it was last analyzed by NVD. It is awaiting reanalysis, which may result in further changes to the information provided. On F5 BIG-IP 16.1.x versions prior to 16.1.2.2, 15.1.x versions prior to 15.1.5.1, 14.1.x versions prior to 14.1.4.6, 13.1.x versions prior to 13.1.5, and all 12.1.x and 11.6.x versions, undisclosed requests may bypass iControl REST authentication. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated. |
|
Recommended Mitigations
|
|
Detection Methods N/A |
|
Vulnerable Technologies and Versions Big IP versions: 16.1.0-16.1.2 15.1.0-15.1.5 14.1.0-14.1.4 13.1.0-13.1.4 12.1.0-12.1.6 11.6.1-11.6.5 |
Table XVI: Apache CVE-2022-24112
|
Apache CVE-2022-24112 CVSS 3.0: 9.8 (Critical) |
|
Vulnerability Description A malicious actor can abuse the batch-requests plugin to send requests to bypass the IP restriction of Admin API. A default configuration of Apache APISIX (with default API key) is vulnerable to remote code execution. When the admin key was changed or the port of Admin API was changed to a port different from the data panel, the impact is lower. But there is still a risk to bypass the IP restriction of Apache APISIX's data panel. There is a check in the batch-requests plugin which overrides the client IP with its real remote IP. But due to a bug in the code, this check can be bypassed. |
|
Recommended Mitigations
|
|
Detection Methods N/A |
|
Vulnerable Technologies and Versions Apache APISIX between 1.3 and 2.12.1 (excluding 2.12.1) LTS versions of Apache APISIX between 2.10.0 and 2.10.4 |
Table XVII: ZOHO CVE-2021-40539
|
ZOHO CVE-2021-40539 CVSS 3.0: 9.8 (Critical) |
|
Vulnerability Description Zoho ManageEngine ADSelfService Plus version 6113 and prior is vulnerable to REST API authentication bypass with resultant remote code execution. |
|
Recommended Mitigations
|
|
Detection Methods
|
|
Vulnerable Technologies and Versions Zoho Corp ManageEngine ADSelfService Plus |
Table XVIII: Microsoft CVE-2021-26857
|
Microsoft CVE-2021-26857 CVSS 3.0: 7.8 (High) |
|
Vulnerability Description Microsoft Exchange Server remote code execution vulnerability. This CVE ID differs from CVE-2021-26412, CVE-2021-26854, CVE-2021-26855, CVE-2021-26858, CVE-2021-27065, and CVE-2021-27078. |
|
Recommended Mitigations
|
|
Detection Methods
|
|
Vulnerable Technologies and Versions Microsoft Exchange Servers |
Table XIX: Microsoft CVE-2021-26858
|
Microsoft CVE-2021-26858 CVSS 3.0: 7.8 (High) |
|
Vulnerability Description Microsoft Exchange Server remote code execution vulnerability. This CVE ID differs from CVE-2021-26412, CVE-2021-26854, CVE-2021-26855, CVE-2021-26858, CVE-2021-27065, and CVE-2021-27078. |
|
Recommended Mitigations
|
|
Detection Methods
|
|
Vulnerable Technologies and Versions Microsoft Exchange Servers |
Table XX: Microsoft CVE-2021-27065
|
Microsoft CVE-2021-27065 CVSS 3.0: 7.8 (High) |
|
Vulnerability Description Microsoft Exchange Server remote code execution vulnerability. This CVE ID differs from CVE-2021-26412, CVE-2021-26854, CVE-2021-26855, CVE-2021-26858, CVE-2021-27065, and CVE-2021-27078. |
|
Recommended Mitigations
|
|
Detection Methods
|
|
Vulnerable Technologies and Versions Microsoft Exchange Servers |
|
References https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-27065 |
Table XXI: Apache CVE-2021-41773
|
Apache CVE-2021-41773 CVSS 3.0: 7.5 (High) |
|
Vulnerability Description This vulnerability has been modified since it was last analyzed by NVD. It is awaiting reanalysis, which may result in further changes to the information provided. A flaw was found in a change made to path normalization in Apache HTTP Server 2.4.49. A malicious actor could use a path traversal attack to map URLs to files outside the directories configured by Alias-like directives. If files outside of these directories are not protected by the usual default configuration "require all denied," these requests can succeed. Enabling CGI scripts for these aliased paths could allow for remote code execution. This issue is known to be exploited in the wild. This issue only affects Apache 2.4.49 and not earlier versions. The fix in Apache HTTP Server 2.4.50 is incomplete (see CVE-2021-42013). |
|
Recommended Mitigations
|
|
Detection Methods
|
|
Vulnerable Technologies and Versions Apache HTTP Server 2.4.49 and 2.4.50 Fedoraproject Fedora 34 and 35 Oracle Instantis Enterprise Track 17.1-17.3 Netapp Cloud Backup |
Revisions
Initial Publication: October 6, 2022
Summary
Actions to take today to mitigate cyber threats from ransomware:
• Install updates for operating systems, software, and firmware as soon as they are released.
• Require phishing-resistant MFA for as many services as possible.
• Train users to recognize and report phishing attempts.
Note: This joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.
The Federal Bureau of Investigation (FBI), Cybersecurity and Infrastructure Security Agency (CISA), and Department of Health and Human Services (HHS) are releasing this joint CSA to provide information on the “Daixin Team,” a cybercrime group that is actively targeting U.S. businesses, predominantly in the Healthcare and Public Health (HPH) Sector, with ransomware and data extortion operations.
This joint CSA provides TTPs and IOCs of Daixin actors obtained from FBI threat response activities and third-party reporting.
Download the PDF version of this report: pdf, 591 KB
Download the IOCs: .stix 23.2 kb
Technical Details
Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 11. See MITRE ATT&CK for Enterprise for all referenced tactics and techniques.
Cybercrime actors routinely target HPH Sector organizations with ransomware:
- As of October 2022, per FBI Internet Crime Complaint Center (IC3) data, specifically victim reports across all 16 critical infrastructure sectors, the HPH Sector accounts for 25 percent of ransomware complaints.
- According to an IC3 annual report in 2021, 649 ransomware reports were made across 14 critical infrastructure sectors; the HPH Sector accounted for the most reports at 148.
The Daixin Team is a ransomware and data extortion group that has targeted the HPH Sector with ransomware and data extortion operations since at least June 2022. Since then, Daixin Team cybercrime actors have caused ransomware incidents at multiple HPH Sector organizations where they have:
- Deployed ransomware to encrypt servers responsible for healthcare services—including electronic health records services, diagnostics services, imaging services, and intranet services, and/or
- Exfiltrated personal identifiable information (PII) and patient health information (PHI) and threatened to release the information if a ransom is not paid.
Daixin actors gain initial access to victims through virtual private network (VPN) servers. In one confirmed compromise, the actors likely exploited an unpatched vulnerability in the organization’s VPN server [T1190]. In another confirmed compromise, the actors used previously compromised credentials to access a legacy VPN server [T1078] that did not have multifactor authentication (MFA) enabled. The actors are believed to have acquired the VPN credentials through the use of a phishing email with a malicious attachment [T1598.002].
After obtaining access to the victim’s VPN server, Daixin actors move laterally via Secure Shell (SSH) [T1563.001] and Remote Desktop Protocol (RDP) [T1563.002]. Daixin actors have sought to gain privileged account access through credential dumping [T1003] and pass the hash [T1550.002]. The actors have leveraged privileged accounts to gain access to VMware vCenter Server and reset account passwords [T1098] for ESXi servers in the environment. The actors have then used SSH to connect to accessible ESXi servers and deploy ransomware [T1486] on those servers.
According to third-party reporting, the Daixin Team’s ransomware is based on leaked Babuk Locker source code. This third-party reporting as well as FBI analysis show that the ransomware targets ESXi servers and encrypts files located in /vmfs/volumes/ with the following extensions: .vmdk, .vmem, .vswp, .vmsd, .vmx, and .vmsn. A ransom note is also written to /vmfs/volumes/. See Figure 1 for targeted file system path and Figure 2 for targeted file extensions list. Figure 3 and Figure 4 include examples of ransom notes. Note that in the Figure 3 ransom note, Daixin actors misspell “Daixin” as “Daxin.”
Figure 1: Daixin Team – Ransomware Targeted File Path
Figure 2: Daixin Team – Ransomware Targeted File Extensions
Figure 3: Example 1 of Daixin Team Ransomware Note
Figure 4: Example 2 of Daixin Team Ransomware Note
In addition to deploying ransomware, Daixin actors have exfiltrated data [TA0010] from victim systems. In one confirmed compromise, the actors used Rclone—an open-source program to manage files on cloud storage—to exfiltrate data to a dedicated virtual private server (VPS). In another compromise, the actors used Ngrok—a reverse proxy tool for proxying an internal service out onto an Ngrok domain—for data exfiltration [T1567].
MITRE ATT&CK TACTICS AND TECHNIQUES
See Table 1 for all referenced threat actor tactics and techniques included in this advisory.
Table 1: Daixin Actors’ ATT&CK Techniques for Enterprise
|
Reconnaissance |
||
|
Technique Title |
ID |
Use |
|
Phishing for Information: Spearphishing Attachment |
Daixin actors have acquired the VPN credentials (later used for initial access) by a phishing email with a malicious attachment. |
|
|
Initial Access |
||
|
Technique Title |
ID |
Use |
|
Exploit Public-Facing Application |
Daixin actors exploited an unpatched vulnerability in a VPN server to gain initial access to a network. |
|
|
Valid Accounts |
Daixin actors use previously compromised credentials to access servers on the target network. |
|
|
Persistence |
||
|
Technique Title |
ID |
Use |
|
Account Manipulation |
Daixin actors have leveraged privileged accounts to reset account passwords for VMware ESXi servers in the compromised environment. |
|
|
Credential Access |
||
|
Technique Title |
ID |
Use |
|
OS Credential Dumping |
Daixin actors have sought to gain privileged account access through credential dumping. |
|
|
Lateral Movement |
||
|
Technique Title |
ID |
Use |
|
Remote Service Session Hijacking: SSH Hijacking |
Daixin actors use SSH and RDP to move laterally across a network. |
|
|
Remote Service Session Hijacking: RDP Hijacking |
Daixin actors use RDP to move laterally across a network. |
|
|
Use Alternate Authentication Material: Pass the Hash |
Daixin actors have sought to gain privileged account access through pass the hash. |
|
|
Exfiltration |
||
|
Technique Title |
ID |
Use |
|
Exfiltration Over Web Service |
Daixin Team members have used Ngrok for data exfiltration over web servers. |
|
|
Impact |
||
|
Technique Title |
ID |
Use |
|
Data Encrypted for Impact |
Daixin actors have encrypted data on target systems or on large numbers of systems in a network to interrupt availability to system and network resources. |
INDICATORS OF COMPROMISE
See Table 2 for IOCs obtained from third-party reporting.
Table 2: Daixin Team IOCs – Rclone Associated SHA256 Hashes
|
File |
SHA256 |
|
rclone-v1.59.2-windows-amd64git-log.txt |
9E42E07073E03BDEA4CD978D9E7B44A9574972818593306BE1F3DCFDEE722238 |
|
rclone-v1.59.2-windows-amd64rclone.1 |
19ED36F063221E161D740651E6578D50E0D3CACEE89D27A6EBED4AB4272585BD |
|
rclone-v1.59.2-windows-amd64rclone.exe |
54E3B5A2521A84741DC15810E6FED9D739EB8083CB1FE097CB98B345AF24E939 |
|
rclone-v1.59.2-windows-amd64README.html |
EC16E2DE3A55772F5DFAC8BF8F5A365600FAD40A244A574CBAB987515AA40CBF |
|
rclone-v1.59.2-windows-amd64README.txt |
475D6E80CF4EF70926A65DF5551F59E35B71A0E92F0FE4DD28559A9DEBA60C28 |
Mitigations
FBI, CISA, and HHS urge HPH Sector organizations to implement the following to protect against Daixin and related malicious activity:
- Install updates for operating systems, software, and firmware as soon as they are released. Prioritize patching VPN servers, remote access software, virtual machine software, and known exploited vulnerabilities. Consider leveraging a centralized patch management system to automate and expedite the process.
- Require phishing-resistant MFA for as many services as possible—particularly for webmail, VPNs, accounts that access critical systems, and privileged accounts that manage backups.
- If you use Remote Desktop Protocol (RDP), secure and monitor it.
- Limit access to resources over internal networks, especially by restricting RDP and using virtual desktop infrastructure. After assessing risks, if RDP is deemed operationally necessary, restrict the originating sources, and require multifactor authentication (MFA) to mitigate credential theft and reuse. If RDP must be available externally, use a virtual private network (VPN), virtual desktop infrastructure, or other means to authenticate and secure the connection before allowing RDP to connect to internal devices. Monitor remote access/RDP logs, enforce account lockouts after a specified number of attempts to block brute force campaigns, log RDP login attempts, and disable unused remote access/RDP ports.
- Ensure devices are properly configured and that security features are enabled. Disable ports and protocols that are not being used for business purposes (e.g., RDP Transmission Control Protocol Port 3389).
- Turn off SSH and other network device management interfaces such as Telnet, Winbox, and HTTP for wide area networks (WANs) and secure with strong passwords and encryption when enabled.
- Implement and enforce multi-layer network segmentation with the most critical communications and data resting on the most secure and reliable layer.
- Limit access to data by deploying public key infrastructure and digital certificates to authenticate connections with the network, Internet of Things (IoT) medical devices, and the electronic health record system, as well as to ensure data packages are not manipulated while in transit from man-in-the-middle attacks.
- Use standard user accounts on internal systems instead of administrative accounts, which allow for overarching administrative system privileges and do not ensure least privilege.
- Secure PII/PHI at collection points and encrypt the data at rest and in transit by using technologies such as Transport Layer Security (TPS). Only store personal patient data on internal systems that are protected by firewalls, and ensure extensive backups are available if data is ever compromised.
- Protect stored data by masking the permanent account number (PAN) when it is displayed and rendering it unreadable when it is stored—through cryptography, for example.
- Secure the collection, storage, and processing practices for PII and PHI, per regulations such as the Health Insurance Portability and Accountability Act of 1996 (HIPAA). Implementing HIPAA security measures can prevent the introduction of malware on the system.
- Use monitoring tools to observe whether IoT devices are behaving erratically due to a compromise.
- Create and regularly review internal policies that regulate the collection, storage, access, and monitoring of PII/PHI.
- In addition, the FBI, CISA, and HHS urge all organizations, including HPH Sector organizations, to apply the following recommendations to prepare for, mitigate/prevent, and respond to ransomware incidents.
Preparing for Ransomware
- Maintain offline (i.e., physically disconnected) backups of data, and regularly test backup and restoration. These practices safeguard an organization’s continuity of operations or at least minimize potential downtime from a ransomware incident and protect against data losses.
- Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure.
- Create, maintain, and exercise a basic cyber incident response plan and associated communications plan that includes response procedures for a ransomware incident.
- Organizations should also ensure their incident response and communications plans include response and notification procedures for data breach incidents. Ensure the notification procedures adhere to applicable state laws.
- Refer to applicable state data breach laws and consult legal counsel when necessary.
- For breaches involving electronic health information, you may need to notify the Federal Trade Commission (FTC) or the Department of Health and Human Services, and—in some cases—the media. Refer to the FTC’s Health Breach Notification Rule and U.S. Department of Health and Human Services’ Breach Notification Rule for more information.
- See CISA-Multi-State Information Sharing and Analysis Center (MS-ISAC) Joint Ransomware Guide and CISA Fact Sheet, Protecting Sensitive and Personal Information from Ransomware-Caused Data Breaches, for information on creating a ransomware response checklist and planning and responding to ransomware-caused data breaches.
- Organizations should also ensure their incident response and communications plans include response and notification procedures for data breach incidents. Ensure the notification procedures adhere to applicable state laws.
Mitigating and Preventing Ransomware
- Restrict Server Message Block (SMB) Protocol within the network to only access servers that are necessary and remove or disable outdated versions of SMB (i.e., SMB version 1). Threat actors use SMB to propagate malware across organizations.
- Review the security posture of third-party vendors and those interconnected with your organization. Ensure all connections between third-party vendors and outside software or hardware are monitored and reviewed for suspicious activity.
- Implement listing policies for applications and remote access that only allow systems to execute known and permitted programs.
- Open document readers in protected viewing modes to help prevent active content from running.
- Implement user training program and phishing exercises to raise awareness among users about the risks of visiting suspicious websites, clicking on suspicious links, and opening suspicious attachments. Reinforce the appropriate user response to phishing and spearphishing emails.
- Use strong passwords and avoid reusing passwords for multiple accounts. See CISA Tip Choosing and Protecting Passwords and the National Institute of Standards and Technology’s (NIST’s) Special Publication 800-63B: Digital Identity Guidelines for more information.
- Require administrator credentials to install software.
- Audit user accounts with administrative or elevated privileges and configure access controls with least privilege in mind.
- Install and regularly update antivirus and antimalware software on all hosts.
- Only use secure networks and avoid using public Wi-Fi networks. Consider installing and using a VPN.
- Consider adding an email banner to messages coming from outside your organizations.
- Disable hyperlinks in received emails.
Responding to Ransomware Incidents
If a ransomware incident occurs at your organization:
- Follow your organization’s Ransomware Response Checklist (see Preparing for Ransomware section).
- Scan backups. If possible, scan backup data with an antivirus program to check that it is free of malware. This should be performed using an isolated, trusted system to avoid exposing backups to potential compromise.
- Follow the notification requirements as outlined in your cyber incident response plan.
- Report incidents to the FBI at a local FBI Field Office, CISA at cisa.gov/report, or the U.S. Secret Service (USSS) at a USSS Field Office.
- Apply incident response best practices found in the joint Cybersecurity Advisory, Technical Approaches to Uncovering and Remediating Malicious Activity, developed by CISA and the cybersecurity authorities of Australia, Canada, New Zealand, and the United Kingdom.
Note: FBI, CISA, and HHS strongly discourage paying ransoms as doing so does not guarantee files and records will be recovered. Furthermore, payment may also embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities.
REFERENCES
- Stopransomware.gov is a whole-of-government approach that gives one central location for ransomware resources and alerts.
- Resource to mitigate a ransomware attack: CISA-Multi-State Information Sharing and Analysis Center (MS-ISAC) Joint Ransomware Guide.
- No-cost cyber hygiene services: Cyber Hygiene Services and Ransomware Readiness Assessment.
- Ongoing Threat Alerts and Sector alerts are produced by the Health Sector Cybersecurity Coordination Center (HC3) and can be found at hhs.gov/HC3
- For additional best practices for Healthcare cybersecurity issues see the HHS 405(d) Aligning Health Care Industry Security Approaches at 405d.hhs.gov
REPORTING
The FBI is seeking any information that can be shared, to include boundary logs showing communication to and from foreign IP addresses, a sample ransom note, communications with Daixin Group actors, Bitcoin wallet information, decryptor files, and/or a benign sample of an encrypted file. Regardless of whether you or your organization have decided to pay the ransom, the FBI, CISA, and HHS urge you to promptly report ransomware incidents to a local FBI Field Office, or CISA at cisa.gov/report.
ACKNOWLEDGEMENTS
FBI, CISA, and HHS would like to thank CrowdStrike and the Health Information Sharing and Analysis Center (Health-ISAC) for their contributions to this CSA.
DISCLAIMER
The information in this report is being provided “as is” for informational purposes only. FBI, CISA, and HHS do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by FBI, CISA, or HHS.
Revisions
Initial Publication: October 21, 2022
Summary
From mid-June through mid-July 2022, CISA conducted an incident response engagement at a Federal Civilian Executive Branch (FCEB) organization where CISA observed suspected advanced persistent threat (APT) activity. In the course of incident response activities, CISA determined that cyber threat actors exploited the Log4Shell vulnerability in an unpatched VMware Horizon server, installed XMRig crypto mining software, moved laterally to the domain controller (DC), compromised credentials, and then implanted Ngrok reverse proxies on several hosts to maintain persistence. CISA and the Federal Bureau of Investigation (FBI) assess that the FCEB network was compromised by Iranian government-sponsored APT actors.
CISA and FBI are releasing this Cybersecurity Advisory (CSA) providing the suspected Iranian government-sponsored actors’ tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help network defenders detect and protect against related compromises.
CISA and FBI encourage all organizations with affected VMware systems that did not immediately apply available patches or workarounds to assume compromise and initiate threat hunting activities. If suspected initial access or compromise is detected based on IOCs or TTPs described in this CSA, CISA and FBI encourage organizations to assume lateral movement by threat actors, investigate connected systems (including the DC), and audit privileged accounts. All organizations, regardless of identified evidence of compromise, should apply the recommendations in the Mitigations section of this CSA to protect against similar malicious cyber activity.
For more information on Iranian government-sponsored Iranian malicious cyber activity, see CISA’s Iran Cyber Threat Overview and Advisories webpage and FBI’s Iran Threats webpage.
Download the PDF version of this report: pdf, 528 kb.
For a downloadable copy of the Malware Analysis Report (MAR) accompanying this report, see: MAR 10387061-1.v1.
For a downloadable copy of IOCs, see: AA22-320A.stix, 1.55 mb.
Technical Details
Note: This advisory uses the MITRE ATT&CK for Enterprise framework, version 11. See the MITRE ATT&CK Tactics and Techniques section for a table of the threat actors’ activity mapped to MITRE ATT&CK® tactics and techniques with corresponding mitigation and/or detection recommendations.
Overview
In April 2022, CISA conducted retrospective analysis using EINSTEIN—an FCEB-wide intrusion detection system (IDS) operated and monitored by CISA—and identified suspected APT activity on an FCEB organization’s network. CISA observed bi-directional traffic between the network and a known malicious IP address associated with exploitation of the Log4Shell vulnerability (CVE-2021-44228) in VMware Horizon servers. In coordination with the FCEB organization, CISA initiated threat hunting incident response activities; however, prior to deploying an incident response team, CISA observed additional suspected APT activity. Specifically, CISA observed HTTPS activity from IP address 51.89.181[.]64 to the organization’s VMware server. Based on trusted third-party reporting, 51.89.181[.]64 is a Lightweight Directory Access Protocol (LDAP) server associated with threat actors exploiting Log4Shell. Following HTTPS activity, CISA observed a suspected LDAP callback on port 443 to this IP address. CISA also observed a DNS query for us‐nation‐ny[.]cf that resolved back to 51.89.181[.]64 when the victim server was returning this Log4Shell LDAP callback to the actors’ server.
CISA assessed that this traffic indicated a confirmed compromise based on the successful callback to the indicator and informed the organization of these findings; the organization investigated the activity and found signs of compromise. As trusted-third party reporting associated Log4Shell activity from 51.89.181[.]64 with lateral movement and targeting of DCs, CISA suspected the threat actors had moved laterally and compromised the organization’s DC.
From mid-June through mid-July 2022, CISA conducted an onsite incident response engagement and determined that the organization was compromised as early as February 2022, by likely Iranian government-sponsored APT actors who installed XMRig crypto mining software. The threat actors also moved laterally to the domain controller, compromised credentials, and implanted Ngrok reverse proxies.
Threat Actor Activity
In February 2022, the threat actors exploited Log4Shell [T1190] for initial access [TA0001] to the organization’s unpatched VMware Horizon server. As part of their initial exploitation, CISA observed a connection to known malicious IP address 182.54.217[.]2 lasting 17.6 seconds.
The actors’ exploit payload ran the following PowerShell command [T1059.001] that added an exclusion rule to Windows Defender [T1562.001]:
powershell try{Add-MpPreference -ExclusionPath 'C:'; Write-Host 'added-exclusion'} catch {Write-Host 'adding-exclusion-failed' }; powershell -enc "$BASE64 encoded payload to download next stage and execute it"
The exclusion rule allowlisted the entire c:drive, enabling threat actors to download tools to the c:drive without virus scans. The exploit payload then downloaded mdeploy.text from 182.54.217[.]2/mdepoy.txt to C:userspublicmde.ps1 [T1105]. When executed, mde.ps1 downloaded file.zip from 182.54.217[.]2 and removed mde.ps1 from the disk [T1070.004].
file.zip contained XMRig cryptocurrency mining software and associated configuration files.
- WinRing0x64.sys – XMRig Miner driver
- wuacltservice.exe – XMRig Miner
- config.json – XMRig miner configuration
- RuntimeBroker.exe – Associated file. This file can create a local user account [T1136.001] and tests for internet connectivity by pinging 8.8.8.8 [T1016.001]. The exploit payload created a Scheduled Task [T1053.005] that executed RuntimeBroker.exe daily as SYSTEM. Note: By exploiting Log4Shell, the actors gained access to a VMware service account with administrator and system level access. The Scheduled Task was named RuntimeBrokerService.exe to masquerade as a legitimate Windows task.
See MAR 10387061-1.v1 for additional information, including IOCs, on these four files.
After obtaining initial access and installing XMRig on the VMWare Horizon server, the actors used RDP [T1021.001] and the built-in Windows user account DefaultAccount [T1078.001] to move laterally [TA0008] to a VMware VDI-KMS host. Once the threat actor established themselves on the VDI-KMS host, CISA observed the actors download around 30 megabytes of files from transfer[.]sh server associated with 144.76.136[.]153. The actors downloaded the following tools:
- PsExec – a Microsoft signed tool for system administrators.
- Mimikatz – a credential theft tool.
- Ngrok – a reverse proxy tool for proxying an internal service out onto an Ngrok domain, which the user can then access at a randomly generated subdomain at *.ngrok[.]io. CISA has observed this tool in use by some commercial products for benign purposes; however, this process bypasses typical firewall controls and may be a potentially unwanted application in production environments. Ngrok is known to be used for malicious purposes.[1]
The threat actors then executed Mimikatz on VDI-KMS to harvest credentials and created a rogue domain administrator account [T1136.002]. Using the newly created account, the actors leveraged RDP to propagate to several hosts within the network. Upon logging into each host, the actors manually disabled Windows Defender via the Graphical User Interface (GUI) and implanted Ngrok executables and configuration files. The threat actors were able to implant Ngrok on multiple hosts to ensure Ngrok’s persistence should they lose access to a machine during a routine reboot. The actors were able to proxy [T1090] RDP sessions, which were only observable on the local network as outgoing HTTPS port 443 connections to tunnel.us.ngrok[.]com and korgn.su.lennut[.]com (the prior domain in reverse). It is possible, but was not observed, that the threat actors configured a custom domain, or used other Ngrok tunnel domains, wildcarded here as *.ngrok[.]com, *.ngrok[.]io, ngrok.*.tunnel[.]com, or korgn.*.lennut[.]com.
Once the threat actors established a deep foothold in the network and moved laterally to the domain controller, they executed the following PowerShell command on the Active Directory to obtain a list of all machines attached to the domain [T1018]:
Powershell.exe get-adcomputer -filter * -properties * | select name,operatingsystem,ipv4address >
The threat actors also changed the password for the local administrator account [T1098] on several hosts as a backup should the rogue domain administrator account get detected and terminated. Additionally, the threat actor was observed attempting to dump the Local Security Authority Subsystem Service (LSASS) process [T1003.001] with task manager but this was stopped by additional anti-virus the FCEB organization had installed.
MITRE ATT&CK TACTICS AND TECHNIQUES
See table 1 for all referenced threat actor tactics and techniques in this advisory, as well as corresponding detection and/or mitigation recommendations. For additional mitigations, see the Mitigations section.
|
Initial Access |
|||
|
Technique Title |
ID |
Use |
Recommendations |
|
Exploit Public-Facing Application |
The actors exploited Log4Shell for initial access to the organization’s VMware Horizon server. |
Mitigation/Detection: Use a firewall or web-application firewall and enable logging to prevent and detect potential Log4Shell exploitation attempts [M1050]. Mitigation: Perform regular vulnerability scanning to detect Log4J vulnerabilities and update Log4J software using vendor provided patches [M1016],[M1051]. |
|
|
Execution |
|||
|
Technique Title |
ID |
Use |
Recommendation |
|
Command and Scripting Interpreter: PowerShell |
The actors ran PowerShell commands that added an exclusion rule to Windows Defender. The actors executed PowerShell on the AD to obtain a list of machines on the domain. |
Mitigation: Disable or remove PowerShell for non-administrative users [M1042],[M1026] or enable code-signing to execute only signed scripts [M1045]. Mitigation: Employ anti-malware to automatically detect and quarantine malicious scripts [M1049]. |
|
|
Persistence |
|||
|
Technique Title |
ID |
Use |
Recommendations |
|
Account Manipulation |
The actors changed the password for the local administrator account on several hosts. |
Mitigation: Use multifactor authentication for user and privileged accounts [M1032]. Detection: Monitor events for changes to account objects and/or permissions on systems and the domain, such as event IDs 4738, 4728, and 4670. Monitor for modification of accounts in correlation with other suspicious activity [DS0002]. |
|
|
Create Account: Local Account |
The actors’ malware can create local user accounts. |
Mitigation: Configure access controls and firewalls to limit access to domain controllers and systems used to create and manage accounts. Detection: Monitor executed commands and arguments for actions that are associated with local account creation, such as net user /add , useradd, and dscl -create [DS0017]. Detection: Enable logging for new user creation [DS0002]. |
|
|
Create Account: Domain Account |
The actors used Mimikatz to create a rogue domain administrator account. |
Mitigation: Configure access controls and firewalls to limit access to domain controllers and systems used to create and manage accounts. Detection: Enable logging for new user creation, especially domain administrator accounts [DS0002]. |
|
|
Scheduled Task/Job: Scheduled Task |
The actors’ exploit payload created Scheduled Task RuntimeBrokerService.exe, which executed RuntimeBroker.exe daily as SYSTEM. |
Mitigation: Configure settings for scheduled tasks to force tasks to run under the context of the authenticated account instead of allowing them to run as SYSTEM [M1028]. Detection: Monitor for newly constructed processes and/or command-lines that execute from the svchost.exe in Windows 10 and the Windows Task Scheduler taskeng.exe for older versions of Windows [DS0009] Detection: Monitor for newly constructed scheduled jobs by enabling the Microsoft-Windows-TaskScheduler/Operational setting within the event logging service [DS0003]. |
|
|
Valid Accounts: Default Accounts |
The actors used built-in Windows user account DefaultAccount. |
Mitigation: Change default usernames and passwords immediately after the installation and before deployment to a production environment [M1027]. Detection: Develop rules to monitor logon behavior across default accounts that have been activated or logged into [DS0028]. |
|
|
Defense Evasion |
|||
|
Technique Title |
ID |
Use |
Recommendations |
|
Impair Defenses: Disable or Modify Tools
|
The actors added an exclusion rule to Windows Defender. The tool allowlisted the entire c:drive, enabling the actors to bypass virus scans for tools they downloaded to the c:drive. The actors manually disabled Windows Defender via the GUI. |
Mitigation: Ensure proper user permissions are in place to prevent adversaries from disabling or interfering with security services. [M1018]. Detection: Monitor for changes made to Windows Registry keys and/or values related to services and startup programs that correspond to security tools such as HKLM:SOFTWAREPoliciesMicrosoftWindows Defender [DS0024]. Detection: Monitor for telemetry that provides context for modification or deletion of information related to security software processes or services such as Windows Defender definition files in Windows and System log files in Linux [DS0013]. Detection: Monitor processes for unexpected termination related to security tools/services [DS0009]. |
|
|
Indicator Removal on Host: File Deletion |
The actors removed malicious file mde.ps1 from the dis. |
Detection: Monitor executed commands and arguments for actions that could be utilized to unlink, rename, or delete files [DS0017]. Detection: Monitor for unexpected deletion of files from the system [DS0022]. |
|
|
Credential Access |
|||
|
Technique Title |
ID |
Use |
Recommendations |
|
OS Credential Dumping: LSASS Memory |
The actors were observed trying to dump LSASS process. |
Mitigation: With Windows 10, Microsoft implemented new protections called Credential Guard to protect the LSA secrets that can be used to obtain credentials through forms of credential dumping [M1043] Mitigation: On Windows 10, enable Attack Surface Reduction (ASR) rules to secure LSASS and prevent credential stealing [M1040]. Mitigation: Ensure that local administrator accounts have complex, unique passwords across all systems on the network [M1027]. Detection: Monitor for unexpected processes interacting with LSASS.exe. Common credential dumpers such as Mimikatz access LSASS.exe by opening the process, locating the LSA secrets key, and decrypting the sections in memory where credential details are stored. [DS0009]. Detection: Monitor executed commands and arguments that may attempt to access credential material stored in the process memory of the LSASS [DS0017]. |
|
|
Credentials from Password Stores |
The actors used Mimikatz to harvest credentials. |
Mitigation: Organizations may consider weighing the risk of storing credentials in password stores and web browsers. If system, software, or web browser credential disclosure is a significant concern, technical controls, policy, and user training may be used to prevent storage of credentials in improper locations [M1027]. Detection: Monitor for processes being accessed that may search for common password storage locations to obtain user credentials [DS0009]. Detection: Monitor executed commands and arguments that may search for common password storage locations to obtain user credentials [DS0017]. |
|
|
Discovery |
|||
|
Technique Title |
ID |
Use |
Recommendations |
|
Remote System Discovery |
The actors executed a PowerShell command on the AD to obtain a list of all machines attached to the domain. |
Detection: Monitor executed commands and arguments that may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for lateral movement [DS0017]. Detection: Monitor for newly constructed network connections associated with pings/scans that may attempt to get a listing of other systems by IP address, hostname, or other logical identifier on a network that may be used for lateral movement [DS0029]. Detection: Monitor for newly executed processes that can be used to discover remote systems, such as ping.exe and tracert.exe, especially when executed in quick succession [DS0009]. |
|
|
System Network Configuration Discovery: Internet Connection Discovery |
The actors’ malware tests for internet connectivity by pinging 8.8.8.8. |
Mitigation: Monitor executed commands, arguments [DS0017] and executed processes (e.g., tracert or ping) [DS0009] that may check for internet connectivity on compromised systems. |
|
|
Lateral Movement |
|||
|
Technique Title |
ID |
Use |
Recommendations |
|
Remote Services: Remote Desktop Protocol |
The actors used RDP to move laterally to multiple hosts on the network. |
Mitigation: Use MFA for remote logins [M1032]. Mitigation: Disable the RDP service if it is unnecessary [M1042]. Mitigation: Do not leave RDP accessible from the internet. Enable firewall rules to block RDP traffic between network security zones within a network [M1030]. Mitigation: Consider removing the local Administrators group from the list of groups allowed to log in through RDP [M1026]. Detection: Monitor for user accounts logged into systems associated with RDP (ex: Windows EID 4624 Logon Type 10). Other factors, such as access patterns (ex: multiple systems over a relatively short period of time) and activity that occurs after a remote login, may indicate suspicious or malicious behavior with RDP [DS0028]. |
|
|
Command and Control |
|||
|
Technique Title |
ID |
Use |
Recommendations |
|
Proxy |
The actors used Ngrok to proxy RDP connections and to perform command and control. |
Mitigation: Traffic to known anonymity networks and C2 infrastructure can be blocked through the use of network allow and block lists [M1037]. Detection: Monitor and analyze traffic patterns and packet inspection associated to protocol(s) that do not follow the expected protocol standards and traffic flows (e.g., extraneous packets that do not belong to established flows, gratuitous or anomalous traffic patterns, anomalous syntax, or structure) [DS0029]. |
|
|
Ingress Tool Transfer |
The actors downloaded malware and multiple tools to the network, including PsExec, Mimikatz, and Ngrok. |
Mitigation: Employ anti-malware to automatically detect and quarantine malicious scripts [M1049].
|
INCIDENT RESPONSE
If suspected initial access or compromise is detected based on IOCs or TTPs in this CSA, CISA encourages organizations to assume lateral movement by threat actors and investigate connected systems and the DC.
CISA recommends organizations apply the following steps before applying any mitigations, including patching.
- Immediately isolate affected systems.
- Collect and review relevant logs, data, and artifacts. Take a memory capture of the device(s) and a forensic image capture for detailed analysis.
- Consider soliciting support from a third-party incident response organization that can provide subject matter expertise to ensure the actor is eradicated from the network and to avoid residual issues that could enable follow-on exploitation.
- Report incidents to CISA via CISA’s 24/7 Operations Center (report@cisa.gov or 888-282-0870) or your local FBI field office, or FBI’s 24/7 Cyber Watch (CyWatch) at (855) 292-3937 or by e-mail at CyWatch@fbi.gov.
Mitigations
CISA and FBI recommend implementing the mitigations below and in Table 1 to improve your organization's cybersecurity posture on the basis of threat actor behaviors.
- Install updated builds to ensure affected VMware Horizon and UAG systems are updated to the latest version.
- If updates or workarounds were not promptly applied following VMware’s release of updates for Log4Shell in December 2021, treat those VMware Horizon systems as compromised. Follow the pro-active incident response procedures outlined above prior to applying updates. If no compromise is detected, apply these updates as soon as possible.
- See VMware Security Advisory VMSA-2021-0028.13 and VMware Knowledge Base (KB) 87073 to determine which VMware Horizon components are vulnerable.
- Note: Until the update is fully implemented, consider removing vulnerable components from the internet to limit the scope of traffic. While installing the updates, ensure network perimeter access controls are as restrictive as possible.
- If upgrading is not immediately feasible, see KB87073 and KB87092 for vendor-provided temporary workarounds. Implement temporary solutions using an account with administrative privileges. Note that these temporary solutions should not be treated as permanent fixes; vulnerable components should be upgraded to the latest build as soon as possible.
- Prior to implementing any temporary solution, ensure appropriate backups have been completed.
- Verify successful implementation of mitigations by executing the vendor supplied script Horizon_Windows_Log4j_Mitigations.zip without parameters to ensure that no vulnerabilities remain. See KB87073 for details.
- If updates or workarounds were not promptly applied following VMware’s release of updates for Log4Shell in December 2021, treat those VMware Horizon systems as compromised. Follow the pro-active incident response procedures outlined above prior to applying updates. If no compromise is detected, apply these updates as soon as possible.
- Keep all software up to date and prioritize patching known exploited vulnerabilities (KEVs).
- Minimize the internet-facing attack surface by hosting essential services on a segregated DMZ, ensuring strict network perimeter access controls, and not hosting internet-facing services that are not essential to business operations. Where possible, implement regularly updated web application firewalls (WAF) in front of public-facing services. WAFs can protect against web-based exploitation using signatures and heuristics that are likely to block or alert on malicious traffic.
- Use best practices for identity and access management (IAM) by implementing phishing resistant multifactor authentication (MFA), enforcing use of strong passwords, regularly auditing administrator accounts and permissions, and limiting user access through the principle of least privilege. Disable inactive accounts uniformly across the AD, MFA systems, etc.
- If using Windows 10 version 1607 or Windows Server 2016 or later, monitor or disable Windows DefaultAccount, also known as the Default System Managed Account (DSMA).
- Audit domain controllers to log successful Kerberos Ticket Granting Service (TGS) requests and ensure the events are monitored for anomalous activity.
- Secure accounts.
- Enforce the principle of least privilege. Administrator accounts should have the minimum permission necessary to complete their tasks.
- Ensure there are unique and distinct administrative accounts for each set of administrative tasks.
- Create non-privileged accounts for privileged users and ensure they use the non-privileged accounts for all non-privileged access (e.g., web browsing, email access).
- Create a deny list of known compromised credentials and prevent users from using known-compromised passwords.
- Secure credentials by restricting where accounts and credentials can be used and by using local device credential protection features.
- Use virtualizing solutions on modern hardware and software to ensure credentials are securely stored.
- Ensure storage of clear text passwords in LSASS memory is disabled. Note: For Windows 8, this is enabled by default. For more information see Microsoft Security Advisory Update to Improve Credentials Protection and Management.
- Consider disabling or limiting NTLM and WDigest Authentication.
- Implement Credential Guard for Windows 10 and Server 2016 (refer to Microsoft: Manage Windows Defender Credential Guard for more information). For Windows Server 2012R2, enable Protected Process Light for Local Security Authority (LSA).
- Minimize the AD attack surface to reduce malicious ticket-granting activity. Malicious activity such as “Kerberoasting” takes advantage of Kerberos’ TGS and can be used to obtain hashed credentials that threat actors attempt to crack.
VALIDATE SECURITY CONTROLS
In addition to applying mitigations, CISA and FBI recommend exercising, testing, and validating your organization's security program against the threat behaviors mapped to the MITRE ATT&CK for Enterprise framework in this advisory. CISA and FBI recommend testing your existing security controls inventory to assess how they perform against the ATT&CK techniques described in this advisory.
To get started:
- Select an ATT&CK technique described in this advisory (see table 1).
- Align your security technologies against the technique.
- Test your technologies against the technique.
- Analyze your detection and prevention technologies performance.
- Repeat the process for all security technologies to obtain a set of comprehensive performance data.
- Tune your security program, including people, processes, and technologies, based on the data generated by this process.
CISA and FBI recommend continually testing your security program, at scale, in a production environment to ensure optimal performance against the MITRE ATT&CK techniques identified in this advisory.
References
Revisions
Initial Version: November 16, 2022
Summary
Actions to Take Today to Mitigate Cyber Threats from Ransomware:
• Prioritize remediating known exploited vulnerabilities.
• Enable and enforce multifactor authentication with strong passwords
• Close unused ports and remove any application not deemed necessary for day-to-day operations.
Note: This joint Cybersecurity Advisory (CSA) is part of an ongoing #StopRansomware effort to publish advisories for network defenders that detail various ransomware variants and ransomware threat actors. These #StopRansomware advisories include recently and historically observed tactics, techniques, and procedures (TTPs) and indicators of compromise (IOCs) to help organizations protect against ransomware. Visit stopransomware.gov to see all #StopRansomware advisories and to learn more about other ransomware threats and no-cost resources.
The Federal Bureau of Investigation (FBI), the Cybersecurity and Infrastructure Security Agency (CISA), and the Department of Health and Human Services (HHS) are releasing this joint CSA to disseminate known Hive IOCs and TTPs identified through FBI investigations as recently as November 2022.
FBI, CISA, and HHS encourage organizations to implement the recommendations in the Mitigations section of this CSA to reduce the likelihood and impact of ransomware incidents. Victims of ransomware operations should report the incident to their local FBI field office or CISA.
Download the PDF version of this report: pdf, 852.9 kb.
For a downloadable copy of IOCs, see AA22-321A.stix (STIX, 43.6 kb).
Technical Details
Note: This advisory uses the MITRE ATT&CK® for Enterprise framework, version 12. See MITRE ATT&CK for Enterprise for all referenced tactics and techniques.
As of November 2022, Hive ransomware actors have victimized over 1,300 companies worldwide, receiving approximately US$100 million in ransom payments, according to FBI information. Hive ransomware follows the ransomware-as-a-service (RaaS) model in which developers create, maintain, and update the malware, and affiliates conduct the ransomware attacks. From June 2021 through at least November 2022, threat actors have used Hive ransomware to target a wide range of businesses and critical infrastructure sectors, including Government Facilities, Communications, Critical Manufacturing, Information Technology, and especially Healthcare and Public Health (HPH).
The method of initial intrusion will depend on which affiliate targets the network. Hive actors have gained initial access to victim networks by using single factor logins via Remote Desktop Protocol (RDP), virtual private networks (VPNs), and other remote network connection protocols [T1133]. In some cases, Hive actors have bypassed multifactor authentication (MFA) and gained access to FortiOS servers by exploiting Common Vulnerabilities and Exposures (CVE) CVE-2020-12812. This vulnerability enables a malicious cyber actor to log in without a prompt for the user’s second authentication factor (FortiToken) when the actor changes the case of the username.
Hive actors have also gained initial access to victim networks by distributing phishing emails with malicious attachments [T1566.001] and by exploiting the following vulnerabilities against Microsoft Exchange servers [T1190]:
- CVE-2021-31207 - Microsoft Exchange Server Security Feature Bypass Vulnerability
- CVE-2021-34473 - Microsoft Exchange Server Remote Code Execution Vulnerability
- CVE-2021-34523 - Microsoft Exchange Server Privilege Escalation Vulnerability
After gaining access, Hive ransomware attempts to evade detention by executing processes to:
- Identify processes related to backups, antivirus/anti-spyware, and file copying and then terminating those processes to facilitate file encryption [T1562].
- Stop the volume shadow copy services and remove all existing shadow copies via vssadmin on command line or via PowerShell [T1059] [T1490].
- Delete Windows event logs, specifically the System, Security and Application logs [T1070].
Prior to encryption, Hive ransomware removes virus definitions and disables all portions of Windows Defender and other common antivirus programs in the system registry [T1112].
Hive actors exfiltrate data likely using a combination of Rclone and the cloud storage service Mega.nz [T1537]. In addition to its capabilities against the Microsoft Windows operating system, Hive ransomware has known variants for Linux, VMware ESXi, and FreeBSD.
During the encryption process, a file named *.key (previously *.key.*) is created in the root directory (C: or /root/). Required for decryption, this key file only exists on the machine where it was created and cannot be reproduced. The ransom note, HOW_TO_DECRYPT.txt is dropped into each affected directory and states the *.key file cannot be modified, renamed, or deleted, otherwise the encrypted files cannot be recovered [T1486]. The ransom note contains a “sales department” .onion link accessible through a TOR browser, enabling victim organizations to contact the actors through a live chat panel to discuss payment for their files. However, some victims reported receiving phone calls or emails from Hive actors directly to discuss payment.
The ransom note also threatens victims that a public disclosure or leak site accessible on the TOR site, “HiveLeaks”, contains data exfiltrated from victim organizations who do not pay the ransom demand (see figure 1 below). Additionally, Hive actors have used anonymous file sharing sites to disclose exfiltrated data (see table 1 below).
|
https://mega[.]nz |
|
https://send.exploit[.]in |
|
https://ufile[.]io |
|
https://www.sendspace[.]com |
|
https://privatlab[.]net |
|
https://privatlab[.]com |
Once the victim organization contacts Hive actors on the live chat panel, Hive actors communicate the ransom amount and the payment deadline. Hive actors negotiate ransom demands in U.S. dollars, with initial amounts ranging from several thousand to millions of dollars. Hive actors demand payment in Bitcoin.
Hive actors have been known to reinfect—with either Hive ransomware or another ransomware variant—the networks of victim organizations who have restored their network without making a ransom payment.
Indicators of Compromise
Threat actors have leveraged the following IOCs during Hive ransomware compromises. Note: Some of these indicators are legitimate applications that Hive threat actors used to aid in further malicious exploitation. FBI, CISA, and HHS recommend removing any application not deemed necessary for day-to-day operations. See tables 2–3 below for IOCs obtained from FBI threat response investigations as recently as November 2022.
|
Known IOCs - Files |
|
HOW_TO_DECRYPT.txt typically in directories with encrypted files |
|
*.key typically in the root directory, i.e., C: or /root |
|
hive.bat |
|
shadow.bat |
|
asq.r77vh0[.]pw - Server hosted malicious HTA file |
|
asq.d6shiiwz[.]pw - Server referenced in malicious regsvr32 execution |
|
asq.swhw71un[.]pw - Server hosted malicious HTA file |
|
asd.s7610rir[.]pw - Server hosted malicious HTA file |
|
Windows_x64_encrypt.dll |
|
Windows_x64_encrypt.exe |
|
Windows_x32_encrypt.dll |
|
Windows_x32_encrypt.exe |
|
Linux_encrypt |
|
Esxi_encrypt |
|
Known IOCs – Events |
|
System, Security and Application Windows event logs wiped |
|
Microsoft Windows Defender AntiSpyware Protection disabled |
|
Microsoft Windows Defender AntiVirus Protection disabled |
|
Volume shadow copies deleted |
|
Normal boot process prevented |
|
Known IOCs – Logged Processes |
|
wevtutil.exe cl system |
|
wevtutil.exe cl security |
|
wevtutil.exe cl application |
|
vssadmin.exe delete shadows /all /quiet |
|
wmic.exe SHADOWCOPY /nointeractive |
|
wmic.exe shadowcopy delete |
|
bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures |
|
bcdedit.exe /set {default} recoveryenabled no |
|
84.32.188[.]57 |
84.32.188[.]238 |
|
93.115.26[.]251 |
185.8.105[.]67 |
|
181.231.81[.]239 |
185.8.105[.]112 |
|
186.111.136[.]37 |
192.53.123[.]202 |
|
158.69.36[.]149 |
46.166.161[.]123 |
|
108.62.118[.]190 |
46.166.161[.]93 |
|
185.247.71[.]106 |
46.166.162[.]125 |
|
5.61.37[.]207 |
46.166.162[.]96 |
|
185.8.105[.]103 |
46.166.169[.]34 |
|
5.199.162[.]220 |
93.115.25[.]139 |
|
5.199.162[.]229 |
93.115.27[.]148 |
|
89.147.109[.]208 |
83.97.20[.]81 |
|
5.61.37[.]207 |
5.199.162[.]220 |
|
5.199.162[.]229; |
46.166.161[.]93 |
|
46.166.161[.]123; |
46.166.162[.]96 |
|
46.166.162[.]125 |
46.166.169[.]34 |
|
83.97.20[.]81 |
84.32.188[.]238 |
|
84.32.188[.]57 |
89.147.109[.]208 |
|
93.115.25[.]139; |
93.115.26[.]251 |
|
93.115.27[.]148 |
108.62.118[.]190 |
|
158.69.36[.]149/span> |
181.231.81[.]239 |
|
185.8.105[.]67 |
185.8.105[.]103 |
|
185.8.105[.]112 |
185.247.71[.]106 |
|
186.111.136[.]37 |
192.53.123[.]202 |
MITRE ATT&CK TECHNIQUES
See table 4 for all referenced threat actor tactics and techniques listed in this advisory.
|
Initial Access |
||
|
Technique Title |
ID |
Use |
|
External Remote Services |
Hive actors gain access to victim networks by using single factor logins via RDP, VPN, and other remote network connection protocols. |
|
|
Exploit Public-Facing Application |
Hive actors gain access to victim network by exploiting the following Microsoft Exchange vulnerabilities: CVE-2021-34473, CVE-2021-34523, CVE-2021-31207, CVE-2021-42321. |
|
|
Phishing |
Hive actors gain access to victim networks by distributing phishing emails with malicious attachments. |
|
|
Execution |
||
|
Technique Title |
ID |
Use |
|
Command and Scripting Interpreter |
Hive actors looks to stop the volume shadow copy services and remove all existing shadow copies via vssadmin on command line or PowerShell. |
|
|
Defense Evasion |
||
|
Technique Title |
ID |
Use |
|
Indicator Removal on Host |
Hive actors delete Windows event logs, specifically, the System, Security and Application logs. |
|
|
Modify Registry |
Hive actors set registry values for DisableAntiSpyware and DisableAntiVirus to 1. |
|
|
Impair Defenses |
Hive actors seek processes related to backups, antivirus/anti-spyware, and file copying and terminates those processes to facilitate file encryption. |
|
|
Exfiltration |
||
|
Technique Title |
ID |
Use |
|
Transfer Data to Cloud Account |
Hive actors exfiltrate data from victims, using a possible combination of Rclone and the cloud storage service Mega.nz. |
|
|
Impact |
||
|
Technique Title |
|
Use |
|
Data Encrypted for Impact |
Hive actors deploy a ransom note HOW_TO_DECRYPT.txt into each affected directory which states the *.key file cannot be modified, renamed, or deleted, otherwise the encrypted files cannot be recovered. |
|
|
Inhibit System Recovery |
Hive actors looks to stop the volume shadow copy services and remove all existing shadow copies via vssadmin via command line or PowerShell. |
Mitigations
FBI, CISA, and HHS recommend organizations, particularly in the HPH sector, implement the following to limit potential adversarial use of common system and network discovery techniques and to reduce the risk of compromise by Hive ransomware:
- Verify Hive actors no longer have access to the network.
- Install updates for operating systems, software, and firmware as soon as they are released. Prioritize patching VPN servers, remote access software, virtual machine software, and known exploited vulnerabilities. Consider leveraging a centralized patch management system to automate and expedite the process.
- Require phishing-resistant MFA for as many services as possible—particularly for webmail, VPNs, accounts that access critical systems, and privileged accounts that manage backups.
- If used, secure and monitor RDP.
- Limit access to resources over internal networks, especially by restricting RDP and using virtual desktop infrastructure.
- After assessing risks, if you deem RDP operationally necessary, restrict the originating sources and require MFA to mitigate credential theft and reuse.
- If RDP must be available externally, use a VPN, virtual desktop infrastructure, or other means to authenticate and secure the connection before allowing RDP to connect to internal devices.
- Monitor remote access/RDP logs, enforce account lockouts after a specified number of attempts to block brute force campaigns, log RDP login attempts, and disable unused remote access/RDP ports.
- Be sure to properly configure devices and enable security features.
- Disable ports and protocols not used for business purposes, such as RDP Port 3389/TCP.
- Maintain offline backups of data, and regularly maintain backup and restoration. By instituting this practice, the organization ensures they will not be severely interrupted, and/or only have irretrievable data.
- Ensure all backup data is encrypted, immutable (i.e., cannot be altered or deleted), and covers the entire organization’s data infrastructure. Ensure your backup data is not already infected.,
- Monitor cyber threat reporting regarding the publication of compromised VPN login credentials and change passwords/settings if applicable.
- Install and regularly update anti-virus or anti-malware software on all hosts.
- Enable PowerShell Logging including module logging, script block logging and transcription.
- Install an enhanced monitoring tool such as Sysmon from Microsoft for increased logging.
- Review the following additional resources.
- The joint advisory from Australia, Canada, New Zealand, the United Kingdom, and the United States on Technical Approaches to Uncovering and Remediating Malicious Activity provides additional guidance when hunting or investigating a network and common mistakes to avoid in incident handling.
- The Cybersecurity and Infrastructure Security Agency-Multi-State Information Sharing & Analysis Center Joint Ransomware Guide covers additional best practices and ways to prevent, protect, and respond to a ransomware attack.
- StopRansomware.gov is the U.S. Government’s official one-stop location for resources to tackle ransomware more effectively.
If your organization is impacted by a ransomware incident, FBI, CISA, and HHS recommend the following actions.
- Isolate the infected system. Remove the infected system from all networks, and disable the computer’s wireless, Bluetooth, and any other potential networking capabilities. Ensure all shared and networked drives are disconnected.
- Turn off other computers and devices. Power-off and segregate (i.e., remove from the network) the infected computer(s). Power-off and segregate any other computers or devices that share a network with the infected computer(s) that have not been fully encrypted by ransomware. If possible, collect and secure all infected and potentially infected computers and devices in a central location, making sure to clearly label any computers that have been encrypted. Powering-off and segregating infected computers and computers that have not been fully encrypted may allow for the recovery of partially encrypted files by specialists.
- Secure your backups. Ensure that your backup data is offline and secure. If possible, scan your backup data with an antivirus program to check that it is free of malware.
In addition, FBI, CISA, and HHS urge all organizations to apply the following recommendations to prepare for, mitigate/prevent, and respond to ransomware incidents.
Preparing for Cyber Incidents
- Review the security posture of third-party vendors and those interconnected with your organization. Ensure all connections between third-party vendors and outside software or hardware are monitored and reviewed for suspicious activity.
- Implement listing policies for applications and remote access that only allow systems to execute known and permitted programs under an established security policy.
- Document and monitor external remote connections. Organizations should document approved solutions for remote management and maintenance, and immediately investigate if an unapproved solution is installed on a workstation.
- Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, and secure location (i.e., hard drive, storage device, the cloud).
Identity and Access Management
- Require all accounts with password logins (e.g., service account, admin accounts, and domain admin accounts) to comply with National Institute of Standards and Technology (NIST) standards for developing and managing password policies.
- Use longer passwords consisting of at least 8 characters and no more than 64 characters in length.
- Store passwords in hashed format using industry-recognized password managers.
- Add password user “salts” to shared login credentials.
- Avoid reusing passwords.
- Implement multiple failed login attempt account lockouts.
- Disable password “hints.”
- Refrain from requiring password changes more frequently than once per year unless a password is known or suspected to be compromised.
Note: NIST guidance suggests favoring longer passwords instead of requiring regular and frequent password resets. Frequent password resets are more likely to result in users developing password “patterns” cyber criminals can easily decipher. - Require administrator credentials to install software.
- Require phishing-resistant multifactor authentication for all services to the extent possible, particularly for webmail, virtual private networks, and accounts that access critical systems.
- Review domain controllers, servers, workstations, and active directories for new and/or unrecognized accounts.
- Audit user accounts with administrative privileges and configure access controls according to the principle of least privilege.
- Implement time-based access for accounts set at the admin level and higher. For example, the Just-in-Time (JIT) access method provisions privileged access when needed and can support enforcement of the principle of least privilege (as well as the Zero Trust model). This is a process where a network-wide policy is set in place to automatically disable admin accounts at the Active Directory level when the account is not in direct need. Individual users may submit their requests through an automated process that grants them access to a specified system for a set timeframe when they need to support the completion of a certain task.
Protective Controls and Architecture
- Segment networks to prevent the spread of ransomware. Network segmentation can help prevent the spread of ransomware by controlling traffic flows between—and access to—various subnetworks and by restricting adversary lateral movement.
- Identify, detect, and investigate abnormal activity and potential traversal of the indicated ransomware with a networking monitoring tool. To aid in detecting the ransomware, implement a tool that logs and reports all network traffic, including lateral movement activity on a network. Endpoint detection and response (EDR) tools are particularly useful for detecting lateral connections as they have insight into common and uncommon network connections for each host.
- Install, regularly update, and enable real time detection for antivirus software on all hosts.
Vulnerability and Configuration Management
- Consider adding an email banner to emails received from outside your organization.
- Disable command-line and scripting activities and permissions. Privilege escalation and lateral movement often depend on software utilities running from the command line. If threat actors are not able to run these tools, they will have difficulty escalating privileges and/or moving laterally.
- Ensure devices are properly configured and that security features are enabled.
- Restrict Server Message Block (SMB) Protocol within the network to only access necessary servers and remove or disable outdated versions of SMB (i.e., SMB version 1). Threat actors use SMB to propagate malware across organizations.
REFERENCES
- Stopransomware.gov is a whole-of-government approach that gives one central location for ransomware resources and alerts.
- Resource to mitigate a ransomware attack: CISA-Multi-State Information Sharing and Analysis Center (MS-ISAC) Joint Ransomware Guide.
- No-cost cyber hygiene services: Cyber Hygiene Services and Ransomware Readiness Assessment.
INFORMATION REQUESTED
The FBI, CISA, and HHS do not encourage paying a ransom to criminal actors. Paying a ransom may embolden adversaries to target additional organizations, encourage other criminal actors to engage in the distribution of ransomware, and/or fund illicit activities. Paying the ransom also does not guarantee that a victim’s files will be recovered. However, the FBI, CISA, and HHS understand that when businesses are faced with an inability to function, executives will evaluate all options to protect their shareholders, employees, and customers. Regardless of whether you or your organization decide to pay the ransom, the FBI, CISA, and HHS urge you to promptly report ransomware incidents to your local FBI field office, or to CISA at report@cisa.gov or (888) 282-0870. Doing so provides investigators with the critical information they need to track ransomware attackers, hold them accountable under US law, and prevent future attacks.
The FBI may seek the following information that you determine you can legally share, including:
- Recovered executable files
- Live random access memory (RAM) capture
- Images of infected systems
- Malware samples
- IP addresses identified as malicious or suspicious
- Email addresses of the attackers
- A copy of the ransom note
- Ransom amount
- Bitcoin wallets used by the attackers
- Bitcoin wallets used to pay the ransom
- Post-incident forensic reports
DISCLAIMER
The information in this report is being provided “as is” for informational purposes only. FBI, CISA, and HHS do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by FBI, CISA, or HHS.
Revisions
Initial Version: November 17, 2022
Summary
Actions Critical Infrastructure Organizations Should Implement to Immediately Strengthen Their Cyber Posture.
• Patch all systems. Prioritize patching known exploited vulnerabilities.
• Implement multi-factor authentication.
• Use antivirus software.
• Develop internal contact lists and surge support.
Note: this advisory uses the MITRE Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK®) framework, version 10. See the ATT&CK for Enterprise for all referenced threat actor tactics and techniques.
This joint Cybersecurity Advisory (CSA)—authored by the Cybersecurity and Infrastructure Security Agency (CISA), Federal Bureau of Investigation (FBI), and National Security Agency (NSA)—is part of our continuing cybersecurity mission to warn organizations of cyber threats and help the cybersecurity community reduce the risk presented by these threats. This CSA provides an overview of Russian state-sponsored cyber operations; commonly observed tactics, techniques, and procedures (TTPs); detection actions; incident response guidance; and mitigations. This overview is intended to help the cybersecurity community reduce the risk presented by these threats.
CISA, the FBI, and NSA encourage the cybersecurity community—especially critical infrastructure network defenders—to adopt a heightened state of awareness and to conduct proactive threat hunting, as outlined in the Detection section. Additionally, CISA, the FBI, and NSA strongly urge network defenders to implement the recommendations listed below and detailed in the Mitigations section. These mitigations will help organizations improve their functional resilience by reducing the risk of compromise or severe business degradation.
- Be prepared. Confirm reporting processes and minimize personnel gaps in IT/OT security coverage. Create, maintain, and exercise a cyber incident response plan, resilience plan, and continuity of operations plan so that critical functions and operations can be kept running if technology systems are disrupted or need to be taken offline.
- Enhance your organization’s cyber posture. Follow best practices for identity and access management, protective controls and architecture, and vulnerability and configuration management.
- Increase organizational vigilance. Stay current on reporting on this threat. Subscribe to CISA’s mailing list and feeds to receive notifications when CISA releases information about a security topic or threat.
CISA, the FBI, and NSA encourage critical infrastructure organization leaders to review CISA Insights: Preparing for and Mitigating Cyber Threats for information on reducing cyber threats to their organization.
Click here for a PDF version of this report.
Technical Details
Historically, Russian state-sponsored advanced persistent threat (APT) actors have used common but effective tactics—including spearphishing, brute force, and exploiting known vulnerabilities against accounts and networks with weak security—to gain initial access to target networks. Vulnerabilities known to be exploited by Russian state-sponsored APT actors for initial access include:
- CVE-2018-13379 FortiGate VPNs
- CVE-2019-1653 Cisco router
- CVE-2019-2725 Oracle WebLogic Server
- CVE-2019-7609 Kibana
- CVE-2019-9670 Zimbra software
- CVE-2019-10149 Exim Simple Mail Transfer Protocol
- CVE-2019-11510 Pulse Secure
- CVE-2019-19781 Citrix
- CVE-2020-0688 Microsoft Exchange
- CVE-2020-4006 VMWare (note: this was a zero-day at time.)
- CVE-2020-5902 F5 Big-IP
- CVE-2020-14882 Oracle WebLogic
- CVE-2021-26855 Microsoft Exchange (Note: this vulnerability is frequently observed used in conjunction with CVE-2021-26857, CVE-2021-26858, and CVE-2021-27065)
Russian state-sponsored APT actors have also demonstrated sophisticated tradecraft and cyber capabilities by compromising third-party infrastructure, compromising third-party software, or developing and deploying custom malware. The actors have also demonstrated the ability to maintain persistent, undetected, long-term access in compromised environments—including cloud environments—by using legitimate credentials.
In some cases, Russian state-sponsored cyber operations against critical infrastructure organizations have specifically targeted operational technology (OT)/industrial control systems (ICS) networks with destructive malware. See the following advisories and alerts for information on historical Russian state-sponsored cyber-intrusion campaigns and customized malware that have targeted ICS:
- ICS Advisory ICS Focused Malware – Havex
- ICS Alert Ongoing Sophisticated Malware Campaign Compromising ICS (Update E)
- ICS Alert Cyber-Attack Against Ukrainian Critical Infrastructure
- Technical Alert CrashOverride Malware
- CISA MAR HatMan: Safety System Targeted Malware (Update B)
- CISA ICS Advisory Schneider Electric Triconex Tricon (Update B)
Russian state-sponsored APT actors have used sophisticated cyber capabilities to target a variety of U.S. and international critical infrastructure organizations, including those in the Defense Industrial Base as well as the Healthcare and Public Health, Energy, Telecommunications, and Government Facilities Sectors. High-profile cyber activity publicly attributed to Russian state-sponsored APT actors by U.S. government reporting and legal actions includes:
- Russian state-sponsored APT actors targeting state, local, tribal, and territorial (SLTT) governments and aviation networks, September 2020, through at least December 2020. Russian state-sponsored APT actors targeted dozens of SLTT government and aviation networks. The actors successfully compromised networks and exfiltrated data from multiple victims.
- Russian state-sponsored APT actors’ global Energy Sector intrusion campaign, 2011 to 2018. These Russian state-sponsored APT actors conducted a multi-stage intrusion campaign in which they gained remote access to U.S. and international Energy Sector networks, deployed ICS-focused malware, and collected and exfiltrated enterprise and ICS-related data.
- Russian state-sponsored APT actors’ campaign against Ukrainian critical infrastructure, 2015 and 2016. Russian state-sponsored APT actors conducted a cyberattack against Ukrainian energy distribution companies, leading to multiple companies experiencing unplanned power outages in December 2015. The actors deployed BlackEnergy malware to steal user credentials and used its destructive malware component, KillDisk, to make infected computers inoperable. In 2016, these actors conducted a cyber-intrusion campaign against a Ukrainian electrical transmission company and deployed CrashOverride malware specifically designed to attack power grids.
For more information on recent and historical Russian state-sponsored malicious cyber activity, see the referenced products below or cisa.gov/Russia.
- Joint FBI-DHS-CISA CSA Russian Foreign Intelligence Service (SVR) Cyber Operations: Trends and Best Practices for Network Defenders
- Joint NSA-FBI-CISA CSA Russian GRU Conducting Global Brute Force Campaign to Compromise Enterprise and Cloud Environments
- Joint FBI-CISA CSA Russian State-Sponsored Advanced Persistent Threat Actor Compromises U.S. Government Targets
- Joint CISA-FBI CSA APT Actors Chaining Vulnerabilities against SLTT, Critical Infrastructure, and Elections Organizations
- CISA’s webpage Remediating Networks Affected by the SolarWinds and Active Directory/M365 Compromise
- CISA Alert Russian Government Cyber Activity Targeting Energy Sector and Other Critical Infrastructure Sectors
- CISA ICS Alert: Cyber-Attack Against Ukrainian Critical Infrastructure
Table 1 provides common, publicly known TTPs employed by Russian state-sponsored APT actors, which map to the MITRE ATT&CK for Enterprise framework, version 10. Note: these lists are not intended to be all inclusive. Russian state-sponsored actors have modified their TTPs before based on public reporting.[1] Therefore, CISA, the FBI, and NSA anticipate the Russian state-sponsored actors may modify their TTPs as they deem necessary to reduce their risk of detection.
Table 1: Common Tactics and Techniques Employed by Russian State-Sponsored APT Actors
| Tactic | Technique | Procedure |
|---|---|---|
|
Reconnaissance [TA0043] |
Active Scanning: Vulnerability Scanning [T1595.002] |
|
|
Russian state-sponsored APT actors have performed large-scale scans in an attempt to find vulnerable servers. |
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Phishing for Information [T1598] |
Russian state-sponsored APT actors have conducted spearphishing campaigns to gain credentials of target networks. |
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Resource Development [TA0042] |
Develop Capabilities: Malware [T1587.001] |
Russian state-sponsored APT actors have developed and deployed malware, including ICS-focused destructive malware. |
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Initial Access [TA0001] |
Exploit Public Facing Applications [T1190] |
Russian state-sponsored APT actors use publicly known vulnerabilities, as well as zero-days, in internet-facing systems to gain access to networks. |
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Supply Chain Compromise: Compromise Software Supply Chain [T1195.002] |
Russian state-sponsored APT actors have gained initial access to victim organizations by compromising trusted third-party software. Notable incidents include M.E.Doc accounting software and SolarWinds Orion. |
|
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Execution [TA0002] |
Command and Scripting Interpreter: PowerShell [T1059.003] and Windows Command Shell [T1059.003] |
Russian state-sponsored APT actors have used |
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Persistence [TA0003] |
Valid Accounts [T1078] |
Russian state-sponsored APT actors have used credentials of existing accounts to maintain persistent, long-term access to compromised networks. |
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Credential Access [TA0006] |
Brute Force: Password Guessing [T1110.001] and Password Spraying [T1110.003] |
Russian state-sponsored APT actors have conducted brute-force password guessing and password spraying campaigns. |
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OS Credential Dumping: NTDS [T1003.003] |
Russian state-sponsored APT actors have exfiltrated credentials and exported copies of the Active Directory database |
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Steal or Forge Kerberos Tickets: Kerberoasting [T1558.003] |
Russian state-sponsored APT actors have performed “Kerberoasting,” whereby they obtained the Ticket Granting Service (TGS) Tickets for Active Directory Service Principal Names (SPN) for offline cracking. |
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Credentials from Password Stores [T1555] |
Russian state-sponsored APT actors have used previously compromised account credentials to attempt to access Group Managed Service Account (gMSA) passwords. |
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Exploitation for Credential Access [T1212] |
Russian state-sponsored APT actors have exploited Windows Netlogon vulnerability CVE-2020-1472 to obtain access to Windows Active Directory servers. |
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Unsecured Credentials: Private Keys [T1552.004] |
Russian state-sponsored APT actors have obtained private encryption keys from the Active Directory Federation Services (ADFS) container to decrypt corresponding SAML signing certificates. |
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Command and Control [TA0011] |
Proxy: Multi-hop Proxy [T1090.003] |
Russian state-sponsored APT actors have used virtual private servers (VPSs) to route traffic to targets. The actors often use VPSs with IP addresses in the home country of the victim to hide activity among legitimate user traffic. |
For additional enterprise TTPs used by Russian state-sponsored APT actors, see the ATT&CK for Enterprise pages on APT29, APT28, and the Sandworm Team, respectively. For information on ICS TTPs see the ATT&CK for ICS pages on the Sandworm Team, BlackEnergy 3 malware, CrashOveride malware, BlackEnergy’s KillDisk component, and NotPetya malware.
Detection
Given Russian state-sponsored APT actors demonstrated capability to maintain persistent, long-term access in compromised enterprise and cloud environments, CISA, the FBI, and NSA encourage all critical infrastructure organizations to:
- Implement robust log collection and retention. Without a centralized log collection and monitoring capability, organizations have limited ability to investigate incidents or detect the threat actor behavior described in this advisory. Depending on the environment, examples include:
- Native tools such as M365’s Sentinel.
- Third-party tools, such as Sparrow, Hawk, or CrowdStrike's Azure Reporting Tool (CRT), to review Microsoft cloud environments and to detect unusual activity, service principals, and application activity. Note: for guidance on using these and other detection tools, refer to CISA Alert Detecting Post-Compromise Threat Activity in Microsoft Cloud Environments.
- Look for behavioral evidence or network and host-based artifacts from known Russian state-sponsored TTPs. See table 1 for commonly observed TTPs.
- To detect password spray activity, review authentication logs for system and application login failures of valid accounts. Look for multiple, failed authentication attempts across multiple accounts.
- To detect use of compromised credentials in combination with a VPS, follow the below steps:
- Look for suspicious “impossible logins,” such as logins with changing username, user agent strings, and IP address combinations or logins where IP addresses do not align to the expected user’s geographic location.
- Look for one IP used for multiple accounts, excluding expected logins.
- Look for “impossible travel.” Impossible travel occurs when a user logs in from multiple IP addresses that are a significant geographic distance apart (i.e., a person could not realistically travel between the geographic locations of the two IP addresses during the time period between the logins). Note: implementing this detection opportunity can result in false positives if legitimate users apply VPN solutions before connecting into networks.
- Look for processes and program execution command-line arguments that may indicate credential dumping, especially attempts to access or copy the
ntds.ditfile from a domain controller. - Look for suspicious privileged account use after resetting passwords or applying user account mitigations.
- Look for unusual activity in typically dormant accounts.
- Look for unusual user agent strings, such as strings not typically associated with normal user activity, which may indicate bot activity.
- For organizations with OT/ICS systems:
- Take note of unexpected equipment behavior; for example, unexpected reboots of digital controllers and other OT hardware and software.
- Record delays or disruptions in communication with field equipment or other OT devices. Determine if system parts or components are lagging or unresponsive.
Incident Response
Organizations detecting potential APT activity in their IT or OT networks should:
- Immediately isolate affected systems.
- Secure backups. Ensure your backup data is offline and secure. If possible, scan your backup data with an antivirus program to ensure it is free of malware.
- Collect and review relevant logs, data, and artifacts.
- Consider soliciting support from a third-party IT organization to provide subject matter expertise, ensure the actor is eradicated from the network, and avoid residual issues that could enable follow-on exploitation.
- Report incidents to CISA and/or the FBI via your local FBI field office or the FBI’s 24/7 CyWatch at (855) 292-3937 or CyWatch@fbi.gov.
Note: for OT assets, organizations should have a resilience plan that addresses how to operate if you lose access to—or control of—the IT and/or OT environment. Refer to the Mitigations section for more information.
See the joint advisory from Australia, Canada, New Zealand, the United Kingdom, and the United States on Technical Approaches to Uncovering and Remediating Malicious Activity for guidance on hunting or investigating a network, and for common mistakes in incident handling. CISA, the FBI, and NSA encourage critical infrastructure owners and operators to see CISA’s Federal Government Cybersecurity Incident and Vulnerability Response Playbooks. Although tailored to federal civilian branch agencies, these playbooks provide operational procedures for planning and conducting cybersecurity incident and vulnerability response activities and detail each step for both incident and vulnerability response.
Note: organizations should document incident response procedures in a cyber incident response plan, which organizations should create and exercise (as noted in the Mitigations section).
Mitigations
CISA, the FBI, and NSA encourage all organizations to implement the following recommendations to increase their cyber resilience against this threat.
Be Prepared
Confirm Reporting Processes and Minimize Coverage Gaps
- Develop internal contact lists. Assign main points of contact for a suspected incident as well as roles and responsibilities and ensure personnel know how and when to report an incident.
- Minimize gaps in IT/OT security personnel availability by identifying surge support for responding to an incident. Malicious cyber actors are known to target organizations on weekends and holidays when there are gaps in organizational cybersecurity—critical infrastructure organizations should proactively protect themselves by minimizing gaps in coverage.
- Ensure IT/OT security personnel monitor key internal security capabilities and can identify anomalous behavior. Flag any identified IOCs and TTPs for immediate response. (See table 1 for commonly observed TTPs).
Create, Maintain, and Exercise a Cyber Incident Response, Resilience Plan, and Continuity of Operations Plan
- Create, maintain, and exercise a cyber incident response and continuity of operations plan.
- Ensure personnel are familiar with the key steps they need to take during an incident and are positioned to act in a calm and unified manner. Key questions:
- Do personnel have the access they need?
- Do they know the processes?
- For OT assets/networks,
- Identify a resilience plan that addresses how to operate if you lose access to—or control of—the IT and/or OT environment.
- Identify OT and IT network interdependencies and develop workarounds or manual controls to ensure ICS networks can be isolated if the connections create risk to the safe and reliable operation of OT processes. Regularly test contingency plans, such as manual controls, so that safety critical functions can be maintained during a cyber incident. Ensure that the OT network can operate at necessary capacity even if the IT network is compromised.
- Regularly test manual controls so that critical functions can be kept running if ICS or OT networks need to be taken offline.
- Implement data backup procedures on both the IT and OT networks. Backup procedures should be conducted on a frequent, regular basis. Regularly test backup procedures and ensure that backups are isolated from network connections that could enable the spread of malware.
- In addition to backing up data, develop recovery documents that include configuration settings for common devices and critical OT equipment. This can enable more efficient recovery following an incident.
- Identify a resilience plan that addresses how to operate if you lose access to—or control of—the IT and/or OT environment.
Enhance your Organization’s Cyber Posture
CISA, the FBI, and NSA recommend organizations apply the best practices below for identity and access management, protective controls and architecture, and vulnerability and configuration management.
Identity and Access Management
- Require multi-factor authentication for all users, without exception.
- Require accounts to have strong passwords and do not allow passwords to be used across multiple accounts or stored on a system to which an adversary may have access.
- Secure credentials. Russian state-sponsored APT actors have demonstrated their ability to maintain persistence using compromised credentials.
- Use virtualizing solutions on modern hardware and software to ensure credentials are securely stored.
- Disable the storage of clear text passwords in LSASS memory.
- Consider disabling or limiting New Technology Local Area Network Manager (NTLM) and WDigest Authentication.
- Implement Credential Guard for Windows 10 and Server 2016 (Refer to Microsoft: Manage Windows Defender Credential Guard for more information). For Windows Server 2012R2, enable Protected Process Light for Local Security Authority (LSA).
- Minimize the Active Directory attack surface to reduce malicious ticket-granting activity. Malicious activity such as “Kerberoasting” takes advantage of Kerberos’ TGS and can be used to obtain hashed credentials that attackers attempt to crack.
- Set a strong password policy for service accounts.
- Audit Domain Controllers to log successful Kerberos TGS requests and ensure the events are monitored for anomalous activity.
- Secure accounts.
- Enforce the principle of least privilege. Administrator accounts should have the minimum permission they need to do their tasks.
- Ensure there are unique and distinct administrative accounts for each set of administrative tasks.
- Create non-privileged accounts for privileged users and ensure they use the non- privileged accounts for all non-privileged access (e.g., web browsing, email access).
Protective Controls and Architecture
- Identify, detect, and investigate abnormal activity that may indicate lateral movement by a threat actor or malware. Use network monitoring tools and host-based logs and monitoring tools, such as an endpoint detection and response (EDR) tool. EDR tools are particularly useful for detecting lateral connections as they have insight into common and uncommon network connections for each host.
- Enable strong spam filters.
- Enable strong spam filters to prevent phishing emails from reaching end users.
- Filter emails containing executable files to prevent them from reaching end users.
- Implement a user training program to discourage users from visiting malicious websites or opening malicious attachments.
Note: CISA, the FBI, and NSA also recommend, as a longer-term effort, that critical infrastructure organizations implement network segmentation to separate network segments based on role and functionality. Network segmentation can help prevent lateral movement by controlling traffic flows between—and access to—various subnetworks.
- Appropriately implement network segmentation between IT and OT networks. Network segmentation limits the ability of adversaries to pivot to the OT network even if the IT network is compromised. Define a demilitarized zone that eliminates unregulated communication between the IT and OT networks.
- Organize OT assets into logical zones by taking into account criticality, consequence, and operational necessity. Define acceptable communication conduits between the zones and deploy security controls to filter network traffic and monitor communications between zones. Prohibit ICS protocols from traversing the IT network.
Vulnerability and Configuration Management
- Update software, including operating systems, applications, and firmware on IT network assets, in a timely manner. Prioritize patching known exploited vulnerabilities, especially those CVEs identified in this CSA, and then critical and high vulnerabilities that allow for remote code execution or denial-of-service on internet-facing equipment.
- Consider using a centralized patch management system. For OT networks, use a risk-based assessment strategy to determine the OT network assets and zones that should participate in the patch management program.
- Consider signing up for CISA’s cyber hygiene services, including vulnerability scanning, to help reduce exposure to threats. CISA’s vulnerability scanning service evaluates external network presence by executing continuous scans of public, static IP addresses for accessible services and vulnerabilities.
- Use industry recommended antivirus programs.
- Set antivirus/antimalware programs to conduct regular scans of IT network assets using up-to-date signatures.
- Use a risk-based asset inventory strategy to determine how OT network assets are identified and evaluated for the presence of malware.
- Implement rigorous configuration management programs. Ensure the programs can track and mitigate emerging threats. Review system configurations for misconfigurations and security weaknesses.
- Disable all unnecessary ports and protocols
- Review network security device logs and determine whether to shut off unnecessary ports and protocols. Monitor common ports and protocols for command and control activity.
- Turn off or disable any unnecessary services (e.g., PowerShell) or functionality within devices.
- Ensure OT hardware is in read-only mode.
Increase Organizational Vigilance
- Regularly review reporting on this threat. Consider signing up for CISA notifications to receive timely information on current security issues, vulnerabilities, and high-impact activity.
Resources
- For more information on Russian state-sponsored malicious cyber activity, refer to cisa.gov/Russia.
- Refer to CISA Analysis Report Strengthening Security Configurations to Defend Against Attackers Targeting Cloud Services for steps for guidance on strengthening your organizations cloud security practices.
- Leaders of small businesses and small and local government agencies should see CISA’s Cyber Essentials for guidance on developing an actionable understanding of implementing organizational cybersecurity practices.
- Critical infrastructure owners and operators with OT/ICS networks, should review the following resources for additional information:
- NSA and CISA joint CSA NSA and CISA Recommend Immediate Actions to Reduce Exposure Across Operational Technologies and Control Systems
- CISA factsheet Rising Ransomware Threat to Operational Technology Assets for additional recommendations.
Rewards for Justice Program
If you have information on state-sponsored Russian cyber operations targeting U.S. critical infrastructure, contact the Department of State’s Rewards for Justice Program. You may be eligible for a reward of up to $10 million, which DOS is offering for information leading to the identification or location of any person who, while acting under the direction or control of a foreign government, participates in malicious cyber activity against U.S. critical infrastructure in violation of the Computer Fraud and Abuse Act (CFAA). Contact +1-202-702-7843 on WhatsApp, Signal, or Telegram, or send information via the Rewards for Justice secure Tor-based tips line located on the Dark Web. For more details refer to rewardsforjustice.net/malicious_cyber_activity.
Caveats
The information you have accessed or received is being provided “as is” for informational purposes only. CISA, the FBI, and NSA do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by CISA, the FBI, or NSA.
References
Revisions
- January 11, 2022: Initial Version
This product is provided subject to this Notification and this Privacy & Use policy.
Summary
The Cybersecurity and Infrastructure Security Agency (CISA), the Federal Bureau of Investigation (FBI), National Security Agency (NSA), Australian Cyber Security Centre (ACSC), Canadian Centre for Cyber Security (CCCS), the Computer Emergency Response Team New Zealand (CERT NZ), the New Zealand National Cyber Security Centre (NZ NCSC), and the United Kingdom’s National Cyber Security Centre (NCSC-UK) are releasing this joint Cybersecurity Advisory (CSA) to provide mitigation guidance on addressing vulnerabilities in Apache’s Log4j software library: CVE-2021-44228 (known as “Log4Shell”), CVE-2021-45046, and CVE-2021-45105. Sophisticated cyber threat actors are actively scanning networks to potentially exploit Log4Shell, CVE-2021-45046, and CVE-2021-45105 in vulnerable systems. According to public reporting, Log4Shell and CVE-2021-45046 are being actively exploited.
CISA, in collaboration with industry members of CISA’s Joint Cyber Defense Collaborative (JCDC), previously published guidance on Log4Shell for vendors and affected organizations in which CISA recommended that affected organizations immediately apply appropriate patches (or apply workarounds if unable to upgrade), conduct a security review, and report compromises to CISA or the FBI. CISA also issued an Emergency Directive directing U.S. federal civilian executive branch (FCEB) agencies to immediately mitigate Log4j vulnerabilities in solution stacks that accept data from the internet. This joint CSA expands on the previously published guidance by detailing steps that vendors and organizations with IT and/or cloud assets should take to reduce the risk posed by these vulnerabilities.
These steps include:
- Identifying assets affected by Log4Shell and other Log4j-related vulnerabilities,
- Upgrading Log4j assets and affected products to the latest version as soon as patches are available and remaining alert to vendor software updates, and
- Initiating hunt and incident response procedures to detect possible Log4Shell exploitation.
This CSA also provides guidance for affected organizations with operational technology (OT)/industrial control systems (ICS) assets.
Log4j is a Java-based logging library used in a variety of consumer and enterprise services, websites, applications, and OT products. These vulnerabilities, especially Log4Shell, are severe—Apache has rated Log4Shell and CVE-2021-45046 as critical and CVE-2021-45105 as high on the Common Vulnerability Scoring System (CVSS). These vulnerabilities are likely to be exploited over an extended period. CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK strongly urge all organizations to apply the recommendations in the Mitigations section.
CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK encourage leaders of organizations to review NCSC-UK’s blog post, Log4j vulnerability: what should boards be asking?, for information on Log4Shell’s possible impact on their organization as well as response recommendations.
Note: this is an evolving situation, and new vulnerabilities are being discovered. CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK will update this CSA as we learn more about this exploitation and have further guidance to impart.
Click here for a PDF version of this report.
Disclaimer
The information in this report is being provided “as is” for informational purposes only. CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK do not endorse any commercial product or service, including any subjects of analysis. Any reference to specific commercial products, processes, or services by service mark, trademark, manufacturer, or otherwise, does not constitute or imply endorsement, recommendation, or favoring by CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, or NCSC-UK.
Technical Details
Log4Shell
Log4Shell, disclosed on December 10, 2021, is a remote code execution (RCE) vulnerability affecting Apache’s Log4j library, versions 2.0-beta9 to 2.14.1. The vulnerability exists in the action the Java Naming and Directory Interface (JNDI) takes to resolve variables. Affected versions of Log4j contain JNDI features—such as message lookup substitution—that do not protect against adversary-controlled Lightweight Directory Access Protocol (LDAP), Domain Name System (DNS), and other JNDI-related endpoints.
An adversary can exploit Log4Shell by submitting a specially crafted request to a vulnerable system that causes that system to execute arbitrary code. The request allows the adversary to take full control over the system. The adversary can then steal information, launch ransomware, or conduct other malicious activity.
CVE-2021-45046
CVE-2021-45046, disclosed on December 13, 2021, enables a remote attacker to cause RCE, a denial-of-service (DoS) condition, or other effects in certain non-default configurations. This vulnerability affects all versions of Log4j from 2.0-beta9 through 2.12.1 and 2.13.0 through 2.15.0. In response, Apache released Log4j version 2.16.0 (Java 8).
CVE-2021- 45105
CVE-2021-45105, disclosed on December 16, 2021, enables a remote attacker to cause a DoS condition or other effects in certain non-default configurations. According to Apache, when the logging configuration uses a non-default Pattern Layout with a Context Lookup (for example, $${ctx:loginId}), attackers with control over Thread Context Map (MDC) input data can craft malicious input data that contains a recursive lookup, resulting in a StackOverflowError that will terminate the process. In response, Apache released Log4j version 2.17.0 (Java 8).
Impact
Log4Shell and CVE-2021-45046—rated as critical vulnerabilities by Apache—are severe because Java is used extensively across IT and OT platforms, they are easy to exploit, and applying mitigations is resource intensive. Log4Shell is especially critical because it allows malicious actors to remotely run code on vulnerable networks and take full control of systems.
According to public reporting, exploitation of Log4Shell began on or around December 1, 2021, and a proof-of-concept exploit is publicly available for this vulnerability. The FBI has observed attempted exploitation and widespread scanning of the Log4j vulnerability to gain access to networks to deploy cryptomining and botnet malware. The FBI assesses this vulnerability may be exploited by sophisticated cyber threat actors and incorporated into existing cyber criminal schemes that are looking to adopt increasingly sophisticated obfuscation techniques. According to public reporting, CVE-2021-45046 is being actively exploited as well.
CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK assess that exploitation of these vulnerabilities, especially Log4Shell, is likely to increase and continue over an extended period. Given the severity of the vulnerabilities and likely increased exploitation, CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK strongly urge all organizations to apply the recommendations in the Mitigations section to identify, mitigate, and update affected assets.
For more information on these vulnerabilities, see the Apache Log4j Security Vulnerabilities webpage.
Mitigations
Vendors
CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK encourage vendors to:
- Immediately identify, mitigate, and update affected products that use Log4j to the latest patched version.
- For environments using Java 8 or later, upgrade to Log4j version 2.17.0 (released December 17, 2021) or newer.
- For environments using Java 7, upgrade to Log4j version 2.12.3 (released December 21, 2021). Note: Java 7 is currently end of life and organizations should upgrade to Java 8.
- Inform your end users of products that contain these vulnerabilities and strongly urge them to prioritize software updates. CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK strongly recommend vendors take steps to ensure messaging on software updates reaches the widest possible audience (for example, avoid placing relevant information behind paywalls). Note: CISA is actively maintaining a GitHub page and repository with patch information for products known to be affected by Log4Shell. CISA has also notified ICS vendors that may be affected and has asked them to confirm any assets affected by Log4Shell and to apply available mitigations.
Affected Organizations with IT and Cloud Assets
CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK recommend that affected organizations take the following steps to patch these vulnerabilities in their IT and cloud assets and initiate threat hunting to detect possible compromise. Organizations with OT/ICS environments should review the Organizations with OT/ICS Assets section for additional guidance. Note: this guidance includes resources that may or may not be possible for all organizations. CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK recommend that organizations apply the mitigations listed in this advisory to the extent allowed by their environments.
1. Identify vulnerable assets in your environment.
Knowing where Log4j and other affected products exist in your environment is key for protecting your networks.
- Inventory all assets that make use of the Log4j Java library. According to public reporting, adversaries are patching and mitigating assets they compromise to retain control of assets. To avoid missing such defense evasion, organizations should carefully track assets under investigation.
- Assume all versions of Java and Log4j are vulnerable and include them in the inventory.
- Ensure the inventory includes all assets, including cloud assets, regardless of function, operating system, or make. Ensure the inventory includes the following information about each asset
- Software versions
- Timestamps of when last updated and by whom
- User accounts on the asset with their privilege level
- Location of asset in your enterprise topology
- Identify the inventoried assets that are likely vulnerable.
- Use CISA's GitHub repository and CERT/CC's CVE-2021-44228_scanner to identify assets vulnerable to Log4Shell.
Additional resources for detecting vulnerable instances of Log4j are identified below. CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK will update the sources for detection rules as we obtain them. Note: due to the urgency to share this information, CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK have not yet validated this content.
- To identify server applications that may be affected by Log4Shell and CVE-2021-45046, see TrendMicro: Log4J Vulnerability Tester.
- For a list of hashes to help determine if a Java application is running a vulnerable version of Log4j, see:
- Rob Fuller's GitHub page: CVE-2021-44228-Log4Shell-Hashes, and
- The NCC Group’s GitHub page: Cyber-Defence/Intelligence/CVE-2021-44228/.
- For PowerShell to detect vulnerable instances, see:
- Nathan Kula’s GitHub page: PowerShellSnippets/Invoke-Log4ShellScan.ps1, and
- Will Dormann’s GitHub page: checkjndi.ps1.
- For guidance on using Canary Token to test for callback, see Thinkst Canary’s Twitter thread on using Canary Tokens.
- For guidance on using Burpsuite Pro to scan, see:
- Silent Signal’s GitHub page: burp-log4shell, and
- PortSwigger’s GitHub page: active-scan-plus-plus.
- For guidance on using NetMap’s Nmap Scripting Engine (NSE), see Divertor’s GitHub page: nse-log4shell.
- See Florian Roth's GitHub page, Fenrir 0.9.0 - Log4Shell Release, for guidance on using Roth’s Fenrir tool to detect vulnerable instances.
2. Mitigate known and suspected vulnerable assets in your environment.
A. Treat known and suspected vulnerable assets as compromised. These assets should be isolated until they are mitigated and verified (step 2.D). The method of isolation that you should use depends on the criticality of the asset. Possible isolation methods include:
- Physically removing the asset from the network (e.g., unplug the network cable);
- Moving the asset to a “jail VLAN” with heightened monitoring and security;
- Blocking at the network layer (a switch or some other device);
- Implementing a firewall (including web application firewall) with strict port control and logging; or
- Restricting the asset’s communication, especially to the internet and the rest of the enterprise network.
B. Patch Log4j and other affected products to the latest version.
- See the Apache Log4j Security Vulnerabilities webpage (as of December 22, 2021, the latest Log4j version is 2.17.0 for Java 8 and 2.12.3 for Java 7). Note: patching or updating Java is not enough, you must upgrade the Log4j library itself.
- For other affected products, see CISA’s GitHub page.
Note: if your organization is unable to immediately identify and patch vulnerable instances of Log4j, apply appropriate workarounds. CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK recommend using vendor-provided mitigations when available. Due to the rapidly evolving situation, these workarounds should not be considered permanent fixes and organizations should apply the appropriate patch as soon as it is made available. Additional mitigations are identified below; however, organizations should use these mitigations at their own risk as they may be incomplete, temporary, or cause harmful effects, such as application instability, a DoS condition, or log evasion.
- Remove the
Jndilookup.classfrom the class path. [1] - Delete or rename
Jndilookup.class. Note: removal of theJndiManagerwill cause theJndiContextSelectorandJMSAppenderto no longer function). [2] - Apply a hot patch.
- NCC Group: log4j-jndi-be-gone: A simple mitigation for CVE-2021-44228
- Amazon AWS:
- GitHub page: hotpatch-for-apache-log4j2
- Blog: Hotpatch for Apache Log4j
C. Keep an inventory of known and suspected vulnerable assets and what is done with them throughout this process. It is important to track patching because malicious cyber actors may compromise an asset and then patch it to protect their operations. Organizations should keep a meticulous record of vulnerable assets they have patched to identify whether a threat actor may have patched an asset.
D. Verify the mitigation has worked, if possible.
- Scan the patched/mitigated asset with the tools and methods listed in step 1.B. Use more than one method to verify the mitigation was successfully applied.
- Monitor the asset closely.
- Remain alert to changes from vendors for the software on the asset. Additionally, see CISA's GitHub page for known affected products and patch information. CISA will continually update the repository as vendors release patches.
3. Initiate hunt and incident response procedures. Given the widespread exploitation of this vulnerability, CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK encourage all organizations to assume their assets that use Log4j may have been compromised and initiate hunt procedures.
A. Hunt for signs of exploitation and compromise.
- Treat assets that use Log4j as suspect and conduct vigorous forensic investigation of those assets.
- Inspect and monitor accounts across your enterprise that exist on or connect to assets that use Log4j.
- Inspect changes to configurations made since December 1, 2021, and verify they were intended, especially on assets that use Log4j.
- Use CISA’s GitHub page to detect possible exploitation or compromise.
Additional resources to detect possible exploitation or compromise are identified below. Note: due to the urgency to share this information, CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK have not yet validated this content.
- Cisco Talos blog: Threat Advisory: Critical Apache Log4j vulnerability being exploited in the wild
- Curated Intelligence GitHub page: Log4Shell-IOCs (Note: Curated Intelligence notes that the “IOCs shared by these feeds are low-to-medium confidence we [Curated Intelligence] strongly recommend not adding them to a blocklist.”)
- EmergingThreat.net: signatures to assist with detection of CVE-2021-44228 activity
- Florian Roth’s GitHub pages:
- Huntress blog: Critical RCE Vulnerability: log4j - CVE-2021-44228
- Mandiant blog: Now You Serial, Now You Don’t – Systematically Hunting for Deserialization Exploits
- Microsoft Security Response Center: Microsoft’s Response to CVE-2021-44228 Apache Log4j 2
- NCC Group: Log4Shell: Reconnaissance and post exploitation network detection
- Sigma GitHub pages:
B. If compromise is detected, organizations should:
- Initiate incident response procedures. See the joint advisory from ACSC, CCCS, NZ NCSC, CERT NZ, NCSC-UK, and CISA on Technical Approaches to Uncovering and Remediating Malicious Activity for guidance on hunting or investigating a network, and for common mistakes in incident handling. CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK encourage organizations to see CISA’s Federal Government Cybersecurity Incident and Vulnerability Response Playbooks. Although tailored to U.S. FCEB agencies, these playbooks provide operational procedures for planning and conducting cybersecurity incident and vulnerability response activities and detail each step for both incident and vulnerability response.
- Consider reporting compromises immediately to applicable cybersecurity authorities. Organizations are encouraged to be as thorough as possible by including information such as IP addresses/domains used to exploit your infrastructure, exploited applications/servers, administrators contact information, and the start and end dates of the attack.
- U.S. organizations should report compromises to CISA and the FBI.
- Australian organizations can visit cyber.gov.au or call 1300 292 371 (1300 CYBER 1) to report cybersecurity incidents.
- Canadian organizations can report incidents by emailing CCCS at contact@cyber.gc.ca.
- New Zealand organizations can visit NCSC.govt.nz to report incidents.
- UK organizations can report a significant cyber security incident at ncsc.gov.uk/report-an-incident (monitored 24 hrs) or, for urgent assistance, call 03000 200 973.
4. Evaluate and apply other mitigations.
A. Remain alert to changes from vendors for the software on the asset, and immediately apply updates to assets when notified by a vendor that their product has a patch for this vulnerability. Additionally, see CISA's GitHub repository for known affected products and patch information. CISA will continually update the repository as vendors release patches.
B. Continue to monitor Log4J assets closely. Continually use signatures and indicators of compromise that may indicate exploitation.
- See the exploitation and detection resources listed in step 3.A.(4).
- Be aware that there are many ways to obfuscate the exploit string. Do not depend on one detection method to work all the time.
C. Continue to monitor the Apache Log4j Security Vulnerabilities webpage for new updates. Note: as this is an evolving situation and new vulnerabilities in Log4J are being discovered, organizations should ensure their Apache Log4j is up to date. Identify the software your enterprise uses and stay on top of updates as these may be superseded by other updates and fixes.
D. Block specific outbound Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) network traffic.
- Outbound LDAP: for most networks, LDAP is used internally, but it is rare for LDAP requests to be routed outside a network. Organizations should block outbound LDAP or use an allowlist for outbound LDAP to known good destinations. Note: this may be difficult to detect on certain ports without a firewall that does application layer filtering.
- Remote Method Invocation (RMI): for most networks, RMI is either unused or used for internal sources. Organizations should block outbound RMI or use an allowlist for outbound RMI to known good destinations.
- Outbound DNS: organizations using enterprise DNS resolution can block outbound DNS from sources other than identified DNS resolvers. At a minimum, blocking direct outbound DNS from web application servers configured to use enterprise DNS resolution will mitigate the risks to those systems.
Note: blocking attacker internet IP addresses during this event is difficult due to the high volume of scanning from non-malicious researchers and vendors. The false positives on IP addresses are high. Organizations should focus on looking for signs of successful exploitation and not scans.
Affected Organizations with OT/ICS Assets
Due to the pervasiveness of the Apache Log4j software library—and the integration of the library in operational products—CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK strongly recommend that OT asset owners and operators review their operational architecture and enumerate the vulnerability status against current product alerts and advisories. If a product does not have a security advisory specifically addressing the status of the vulnerability, treat it with additional protections. CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK urge patching or deployment of mitigations to reduce the risk of the threat of these vulnerabilities.
Note: CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK recommend prioritizing patching IT devices, especially those with internet connectivity. Affected internet-facing devices as well as laptops, desktops, and tablets are especially susceptible to exploitation of these vulnerabilities. OT/ICS devices—if segmented appropriately from the IT environment—do not face the internet and, as such, have a smaller attack surface to this vulnerability. Exploitation of IT devices may affect OT/ICS devices if there is insufficient network segmentation that prevents lateral movement.
CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK recommend that OT/ICS asset owner/operators take the following guidance into consideration:
- Review operational architecture and enumerate the vulnerability against current product alerts and advisories. If products do not have a security advisory specifically addressing their status of the vulnerability, it is recommended to treat these devices with additional protections.
- Implement the steps listed in the previous section to identify and isolate vulnerable assets in the OT/ICS environment. Understand what type of products in the OT environment would be affected. Many OT/ICS-specific products incorporate vulnerable versions of the Log4j library.
- Use a risk-informed decision-making process to apply the latest version of hotfixes or patches to affected devices as soon as is operationally feasible. If patches cannot be applied, mitigations provided by the product’s manufacturer or reseller should be deployed. Note: CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK recommend, as quality assurance, that users test the update in a test development environment that reflects their production environment prior to installation.
- Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the internet.
- Locate control system networks and remote devices behind firewalls and isolate them from the business network.
When remote access is required, use secure methods such as virtual private networks (VPNs), recognizing VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that a VPN is only as secure as its connected devices.
CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK also remind organizations to perform proper impact analysis and risk assessment prior to deploying defensive measures.
CISA also provides a section for control systems security recommended practices on the ICS webpage on cisa.gov. Several recommended practices are available for reading and download, including Improving Industrial Control Systems Cybersecurity with Defense-in-Depth Strategies.
Additional mitigation guidance and recommended practices are publicly available on the ICS webpage on cisa.gov in the Technical Information Paper, ICS-TIP-12-146-01B--Targeted Cyber Intrusion Detection and Mitigation Strategies.
Organizations observing any suspected malicious activity should follow their established internal procedures and consider reporting compromises immediately.
- U.S. organizations should report compromises to CISA and the FBI.
- Australian organizations can visit cyber.gov.au or call 1300 292 371 (1300 CYBER 1) to report cybersecurity incidents.
- Canadian organizations can report incidents by emailing CCCS at contact@cyber.gc.ca.
- New Zealand organizations can visit NCSC.govt.nz to report incidents.
- UK organizations can report a significant cyber security incident at ncsc.gov.uk/report-an-incident (monitored 24 hrs) or, for urgent assistance, call 03000 200 973.
Resources
For more information, resources, and general guidance, including resources and mitigation guidance from industry members of JCDC, see CISA’s webpage Apache Log4j Vulnerability Guidance. Note: due to the prominent and ever evolving nature of this vulnerability, there are multiple unverified published guidance documents that are geared towards Log4j vulnerabilities. CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, and NCSC-UK encourage all organizations to verify information with trusted sources, such CISA, the FBI, NSA, ACSC, CCCS, CERT NZ, NZ NCSC, NCSC-UK vendors.
References
Revisions
- December 22, 2021: Initial Version
- December 23, 2021: Updated Resource URL
This product is provided subject to this Notification and this Privacy & Use policy.
Summary
This joint Cybersecurity Advisory uses the MITRE Adversarial Tactics, Techniques, and Common Knowledge (ATT&CK®) framework, Version 9. See the ATT&CK for Enterprise framework for referenced threat actor techniques and for mitigations.
This joint advisory is the result of analytic efforts between the Federal Bureau of Investigation (FBI) and the Cybersecurity and Infrastructure Security Agency (CISA) to highlight the cyber threat associated with active exploitation of a newly identified vulnerability (CVE-2021-44077) in Zoho ManageEngine ServiceDesk Plus—IT help desk software with asset management.
CVE-2021-44077, which Zoho rated critical, is an unauthenticated remote code execution (RCE) vulnerability affecting all ServiceDesk Plus versions up to, and including, version 11305. This vulnerability was addressed by the update released by Zoho on September 16, 2021 for ServiceDesk Plus versions 11306 and above. The FBI and CISA assess that advanced persistent threat (APT) cyber actors are among those exploiting the vulnerability. Successful exploitation of the vulnerability allows an attacker to upload executable files and place webshells, which enable the adversary to conduct post-exploitation activities, such as compromising administrator credentials, conducting lateral movement, and exfiltrating registry hives and Active Directory files.
The Zoho update that patched this vulnerability was released on September 16, 2021, along with a security advisory. Additionally, an email advisory was sent to all ServiceDesk Plus customers with additional information. Zoho released a subsequent security advisory on November 22, 2021, and advised customers to patch immediately.
The FBI and CISA are aware of reports of malicious cyber actors likely using exploits against CVE-2021-44077 to gain access [T1190] to ManageEngine ServiceDesk Plus, as early as late October 2021. The actors have been observed using various tactics, techniques and procedures (TTPs), including:
- Writing webshells [T1505.003] to disk for initial persistence
- Obfuscating and Deobfuscating/Decoding Files or Information [T1027 and T1140]
- Conducting further operations to dump user credentials [T1003]
- Living off the land by only using signed Windows binaries for follow-on actions [T1218]
- Adding/deleting user accounts as needed [T1136]
- Stealing copies of the Active Directory database (
NTDS.dit) [T1003.003] or registry hives - Using Windows Management Instrumentation (WMI) for remote execution [T1047]
- Deleting files to remove indicators from the host [T1070.004]
- Discovering domain accounts with the net Windows command [T1087.002]
- Using Windows utilities to collect and archive files for exfiltration [T1560.001]
- Using custom symmetric encryption for command and control (C2) [T1573.001]
The FBI and CISA are proactively investigating this malicious cyber activity:
- The FBI leverages specially trained cyber squads in each of its 56 field offices and CyWatch, the FBI’s 24/7 operations center and watch floor, which provides around-the-clock support to track incidents and communicate with field offices across the country and partner agencies.
- CISA offers a range of no-cost cyber hygiene services to help organizations assess, identify, and reduce their exposure to threats. By requesting these services, organizations of any size could find ways to reduce their risk and mitigate attack vectors.
Sharing technical and/or qualitative information with the FBI and CISA helps empower and amplify our capabilities as federal partners to collect and share intelligence and engage with victims, while working to unmask and hold accountable those conducting malicious cyber activities.
Click here for a PDF version of this report.
Click here for indicators of compromise (IOCs) in STIX format.
Technical Details
Compromise of the affected systems involves exploitation of CVE-2021-44077 in ServiceDesk Plus, allowing the attacker to:
- Achieve an unrestricted file upload through a POST request to the ServiceDesk REST API URL and upload an executable file,
C:ManageEngineServicedeskbinmsiexec.exe, with a SHA256 hash ofecd8c9967b0127a12d6db61964a82970ee5d38f82618d5db4d8eddbb3b5726b7. This executable file serves as a dropper and contains an embedded, encoded Godzilla JAR file. - Gain execution for the dropper through a second POST request to a different REST API URL, which will then decode the embedded Godzilla JAR file and drop it to the filepath
C:ManageEngineServiceDesklibtomcattomcat-postgres.jarwith a SHA256 hash of67ee552d7c1d46885b91628c603f24b66a9755858e098748f7e7862a71baa015.
Confirming a successful compromise of ManageEngine ServiceDesk Plus may be difficult—the attackers are known to run clean-up scripts designed to remove traces of the initial point of compromise and hide any relationship between exploitation of the vulnerability and the webshell.
Targeted Industries
APT cyber actors have targeted Critical Infrastructure Sector industries, including the healthcare, financial services, electronics and IT consulting industries.
Indicators of Compromise
Hashes
Webshell:
67ee552d7c1d46885b91628c603f24b66a9755858e098748f7e7862a71baa015
068D1B3813489E41116867729504C40019FF2B1FE32AAB4716D429780E666324
759bd8bd7a71a903a26ac8d5914e5b0093b96de61bf5085592be6cc96880e088
262cf67af22d37b5af2dc71d07a00ef02dc74f71380c72875ae1b29a3a5aa23d
a44a5e8e65266611d5845d88b43c9e4a9d84fe074fd18f48b50fb837fa6e429d
ce310ab611895db1767877bd1f635ee3c4350d6e17ea28f8d100313f62b87382
75574959bbdad4b4ac7b16906cd8f1fd855d2a7df8e63905ab18540e2d6f1600
5475aec3b9837b514367c89d8362a9d524bfa02e75b85b401025588839a40bcb
Dropper:
ecd8c9967b0127a12d6db61964a82970ee5d38f82618d5db4d8eddbb3b5726b7
Implant:
009d23d85c1933715c3edcccb46438690a66eebbcccb690a7b27c9483ad9d0ac
083bdabbb87f01477f9cf61e78d19123b8099d04c93ef7ad4beb19f4a228589a
342e85a97212bb833803e06621170c67f6620f08cc220cf2d8d44dff7f4b1fa3
NGLite Backdoor:
805b92787ca7833eef5e61e2df1310e4b6544955e812e60b5f834f904623fd9f
3da8d1bfb8192f43cf5d9247035aa4445381d2d26bed981662e3db34824c71fd
5b8c307c424e777972c0fa1322844d4d04e9eb200fe9532644888c4b6386d755
3f868ac52916ebb6f6186ac20b20903f63bc8e9c460e2418f2b032a207d8f21d
342a6d21984559accbc54077db2abf61fd9c3939a4b09705f736231cbc7836ae
7e4038e18b5104683d2a33650d8c02a6a89badf30ca9174576bf0aff08c03e72
KDC Sponge:
3c90df0e02cc9b1cf1a86f9d7e6f777366c5748bd3cf4070b49460b48b4d4090
b4162f039172dcb85ca4b85c99dd77beb70743ffd2e6f9e0ba78531945577665
e391c2d3e8e4860e061f69b894cf2b1ba578a3e91de610410e7e9fa87c07304c
Malicious IIS Module:
bec067a0601a978229d291c82c35a41cd48c6fca1a3c650056521b01d15a72da
Renamed WinRAR:
d0c3d7003b7f5b4a3bd74a41709cfecfabea1f94b47e1162142de76aa7a063c7
Renamed csvde:
7d2780cd9acc516b6817e9a51b8e2889f2dec455295ac6e6d65a6191abadebff
Network Indicators
POST requests sent to the following URLs:
/RestAPI/ImportTechnicians?step=1
Domains:
seed.nkn[.]org
Note: the domain seed.nkn[.]org is a New Kind of Network (NKN) domain that provides legitimate peer to peer networking services utilizing blockchain technology for decentralization. It is possible to have false positive hits in a corporate network environment and it should be considered suspicious to see any software-initiated contacts to this domain or any subdomain.
Log File Analysis
- Check serverOut*.txt log files under C:ManageEngineServiceDesklogs for suspicious log entries matching the following format:
[<time>]|[<date>]|[com.adventnet.servicedesk.setup.action.ImportTechniciansAction]|[INFO]|[62]: fileName is : msiexec.exe]
Filepaths
C:ManageEngineServiceDeskbinmsiexec.exe
C:ManageEngineServiceDesklibtomcattomcat-postgres.jar
C:WindowsTempScriptModule.dll
C:ManageEngineServiceDeskbinScriptModule.dll
C:Windowssystem32ME_ADAudit.exe
c:Users[username]AppDataRoamingADManagerME_ADManager.exe
%ALLUSERPROFILE%MicrosoftWindowsCachessystem.dat
C:ProgramDataMicrosoftCryptoRSAkey.dat
c:windowstempccc.exe
Tactics, Techniques, and Procedures
- Using WMI for lateral movement and remote code execution (in particular,
wmic.exe) - Using plaintext credentials for lateral movement
- Using
pg_dump.exeto dump ManageEngine databases - Dumping
NTDS.ditandSECURITY/SYSTEM/NTUSERregistry hives - Active credential harvesting through
LSASS(KDC Sponge) - Exfiltrating through webshells
- Conducting exploitation activity often through other compromised U.S. infrastructure
- Dropping multiple webshells and/or implants to maintain persistence
- Using renamed versions of
WinRAR,csvde, and other legitimate third-party tools for reconnaissance and exfiltration
Yara Rules
strings:
$s1 = "decrypt(fpath)"
$s2 = "decrypt(fcontext)"
$s3 = "decrypt(commandEnc)"
$s4 = "upload failed!"
$s5 = "sevck"
$s6 = "newid"
condition:
filesize < 15KB and 4 of them
}
strings:
$s1 = "AEScrypt"
$s2 = "AES/CBC/PKCS5Padding"
$s3 = "SecretKeySpec"
$s4 = "FileOutputStream"
$s5 = "getParameter"
$s6 = "new ProcessBuilder"
$s7 = "new BufferedReader"
$s8 = "readLine()"
condition:
filesize < 15KB and 6 of them
}
strings:
$u1 = "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36"
$u2 = "Content-Type: application/soap+xml; charset=UTF-8"
$u3 = "/service/soap"
$u4 = "Good Luck :::)"
$s1 = "zimBR"
$s2 = "log10"
$s3 = "mymain"
$s4 = "urn:zimbraAccount"
$s5 = "/service/upload?fmt=extended,raw"
$s6 = "<query>(in:"inbox" or in:"junk") is:unread</query>"
condition:
(uint16(0) == 0x5A4D and uint32(uint32(0x3C)) == 0x00004550) and filesize < 2MB and 1 of ($u*) and 3 of ($s*)
}
strings:
$s1 = "UEsDBAoAAAAAAI8UXFM" // base64 encoded PK/ZIP header
$s2 = "../lib/tomcat/tomcat-postgres.jar"
$s3 = "RunAsManager.exe"
$s4 = "ServiceDesk"
$s5 = "C:\Users\pwn\documents\visual studio 2015\Projects\payloaddll"
$s6 = "CreateMutexA"
$s7 = "cplusplus_me"
condition:
(uint16(0) == 0x5A4D and uint32(uint32(0x3C)) == 0x00004550) and filesize < 350KB and 4 of them
}
strings:
$s1 = "org/apache/tomcat/SSLFilter.class"
$s2 = "META-INF/services/javax.servlet.ServletContainerInitializer"
$s3 = "org/apache/tomcat/MainFilterInitializer.class"
condition:
uint32(0) == 0x04034B50 and filesize < 50KB and all of them
}
strings:
$s1 = "/mnt/hgfs/CrossC2-2.2"
$s2 = "WHATswrongwithU"
$s3 = "//seed.nkn.org:"
$s4 = "Preylistener"
$s5 = "preyid"
$s6 = "Www-Authenticate"
condition:
(uint16(0) == 0x5A4D and uint32(uint32(0x3C)) == 0x00004550) and filesize < 15MB and 4 of them
}
strings:
$k1 = "kdcsvc.dll"
$k2 = "kdccli.dll"
$k3 = "kdcsvs.dll"
$f1 = "KerbHashPasswordEx3"
$f2 = "KerbFreeKey"
$f3 = "KdcVerifyEncryptedTimeStamp"
$s1 = "download//symbols//%S//%S//%S" wide
$s2 = "KDC Service"
$s3 = "\system.dat"
condition:
(uint16(0) == 0x5A4D and uint32(uint32(0x3C)) == 0x00004550) and filesize < 1MB and 1 of ($k*) and 1 of ($f*) and 1 of ($s*)
Mitigations
Compromise Mitigations
Organizations that identify any activity related to ManageEngine ServiceDesk Plus indicators of compromise within their networks should take action immediately.
Zoho ManageEngine ServiceDesk Plus build 11306, or higher, fixes CVE-2021-44077. ManageEngine initially released a patch for this vulnerability on September 16, 2021. A subsequent security advisory was released on November 22, 2021, and advised customers to patch immediately. Additional information can be found in the Zoho security advisory released on November 22, 2021.
In addition, Zoho has set up a security response plan center that provides additional details, a downloadable tool that can be run on potentially affected systems, and a remediation guide.
FBI and CISA also strongly recommend domain-wide password resets and double Kerberos TGT password resets if any indication is found that the NTDS.dit file was compromised.
Note: Implementing these password resets should not be taken as a comprehensive mitigation in response to this threat; additional steps may be necessary to regain administrative control of your network. Refer to your specific products mitigation guidance for details.
Actions for Affected Organizations
Immediately report as an incident to CISA or the FBI (refer to Contact information section below) the existence of any of the following:
- Identification of indicators of compromise as outlined above.
- Presence of webshell code on compromised ServiceDesk Plus servers.
- Unauthorized access to or use of accounts.
- Evidence of lateral movement by malicious actors with access to compromised systems.
- Other indicators of unauthorized access or compromise.
Contact Information
Recipients of this report are encouraged to contribute any additional information that they may have related to this threat.
For any questions related to this report or to report an intrusion and request resources for incident response or technical assistance, please contact:
- The FBI through the FBI Cyber Division (855-292-3937 or CyWatch@fbi.gov) or a local field office
- CISA (888-282-0870 or Central@cisa.dhs.gov).
Revisions
- December 2, 2021: Initial version
- December 6, 2021: STIX file added
This product is provided subject to this Notification and this Privacy & Use policy.