Alerts

RSS Alerts from National Cyber Awareness System

January 11, 2022
Published by Certrec Corporation on January 11, 2022
Categories

Understanding and Mitigating Russian State-Sponsored Cyber Threats to U.S. Critical Infrastructure

Original release date: January 11, 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.

  1. 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.
  2. Enhance your organization’s cyber posture. Follow best practices for identity and access management, protective controls and architecture, and vulnerability and configuration management.
  3. 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:

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:

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.

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.

Phishing for Information [T1598]

Russian state-sponsored APT actors have conducted spearphishing campaigns to gain credentials of target networks.

Resource Development [TA0042]

Develop Capabilities: Malware [T1587.001]

Russian state-sponsored APT actors have developed and deployed malware, including ICS-focused destructive malware.

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.

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.

Execution [TA0002]

Command and Scripting Interpreter: PowerShell [T1059.003] and Windows Command Shell [T1059.003]

Russian state-sponsored APT actors have used cmd.exe to execute commands on remote machines. They have also used PowerShell to create new tasks on remote machines, identify configuration settings, exfiltrate data, and to execute other commands.

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.

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.

OS Credential Dumping: NTDS [T1003.003]

Russian state-sponsored APT actors have exfiltrated credentials and exported copies of the Active Directory database ntds.dit.

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.

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.

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.

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.

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.dit file 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:

  1. Immediately isolate affected systems. 
  2. 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.
  3. Collect and review relevant logs, data, and artifacts.
  4. 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.
  5. 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.

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.

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December 22, 2021
Published by Certrec Corporation on December 22, 2021
Categories

Mitigating Log4Shell and Other Log4j-Related Vulnerabilities

Original release date: December 22, 2021 | Last revised: December 23, 2021

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:

  1. Immediately identify, mitigate, and update affected products that use Log4j to the latest patched version.
    1. For environments using Java 8 or later, upgrade to Log4j version 2.17.0 (released December 17, 2021) or newer.
    2. 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.
  2. 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.

  1. 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.
    1. Assume all versions of Java and Log4j are vulnerable and include them in the inventory.
    2. 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
      1. Software versions
      2. Timestamps of when last updated and by whom
      3. User accounts on the asset with their privilege level
      4. Location of asset in your enterprise topology
  2. Identify the inventoried assets that are likely vulnerable.
    1. 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.

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.

   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.

  1. 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.
  2. Monitor the asset closely.
  3. 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.

  1. Treat assets that use Log4j as suspect and conduct vigorous forensic investigation of those assets.
  2. Inspect and monitor accounts across your enterprise that exist on or connect to assets that use Log4j.
  3. Inspect changes to configurations made since December 1, 2021, and verify they were intended, especially on assets that use Log4j.
  4. 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.

   B. If compromise is detected, organizations should:

  1. 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.
  2. 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.

  1. See the exploitation and detection resources listed in step 3.A.(4).
  2. 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.

  1. 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. 
  2. 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.
  3. 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:

  1. 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.  
  2. 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.
  3. 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. 
  4. Minimize network exposure for all control system devices and/or systems, and ensure they are not accessible from the internet.
  5. 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.

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December 2, 2021
Published by Certrec Corporation on December 2, 2021
Categories

APT Actors Exploiting CVE-2021-44077 in Zoho ManageEngine ServiceDesk Plus

Original release date: December 2, 2021 | Last revised: December 6, 2021

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:

  1. 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 of ecd8c9967b0127a12d6db61964a82970ee5d38f82618d5db4d8eddbb3b5726b7. This executable file serves as a dropper and contains an embedded, encoded Godzilla JAR file.
  2. 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.jar with a SHA256 hash of 67ee552d7c1d46885b91628c603f24b66a9755858e098748f7e7862a71baa015.

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.exe to dump ManageEngine databases
  • Dumping NTDS.dit and SECURITY/SYSTEM/NTUSER registry 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

rule ReportGenerate_jsp {
   strings:
      $s1 = "decrypt(fpath)"
      $s2 = "decrypt(fcontext)"
      $s3 = "decrypt(commandEnc)"
      $s4 = "upload failed!"
      $s5 = "sevck"
      $s6 = "newid"
   condition:
      filesize < 15KB and 4 of them
}

 

rule EncryptJSP {
   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
}

 

rule ZimbraImplant {
    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*)
}

 

rule GodzillaDropper {
    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
}

 

rule GodzillaJAR {
    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
}

 

rule APT_NGLite {
    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
}

 

rule KDCSponge {
    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:

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.

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November 17, 2021
Published by Certrec Corporation on November 17, 2021
Categories

Iranian Government-Sponsored APT Cyber Actors Exploiting Microsoft Exchange and Fortinet Vulnerabilities in Furtherance of Malicious Activities

Original release date: November 17, 2021 | Last revised: November 19, 2021

Summary

Actions to Take Today to Protect Against Iranian State-Sponsored Malicious Cyber Activity
• Immediately patch software affected by the following vulnerabilities: CVE-2021-34473, 2018-13379, 2020-12812, and 2019-5591.
• Implement multi-factor authentication.
• Use strong, unique passwords.

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 is the result of an analytic effort among the Federal Bureau of Investigation (FBI), the Cybersecurity and Infrastructure Security Agency (CISA), the Australian Cyber Security Centre (ACSC), and the United Kingdom’s National Cyber Security Centre (NCSC) to highlight ongoing malicious cyber activity by an advanced persistent threat (APT) group that FBI, CISA, ACSC, and NCSC assess is associated with the government of Iran. FBI and CISA have observed this Iranian government-sponsored APT group exploit Fortinet vulnerabilities since at least March 2021 and a Microsoft Exchange ProxyShell vulnerability since at least October 2021 to gain initial access to systems in advance of follow-on operations, which include deploying ransomware. ACSC is also aware this APT group has used the same Microsoft Exchange vulnerability in Australia.

The Iranian government-sponsored APT actors are actively targeting a broad range of victims across multiple U.S. critical infrastructure sectors, including the Transportation Sector and the Healthcare and Public Health Sector, as well as Australian organizations. FBI, CISA, ACSC, and NCSC assess the actors are focused on exploiting known vulnerabilities rather than targeting specific sectors. These Iranian government-sponsored APT actors can leverage this access for follow-on operations, such as data exfiltration or encryption, ransomware, and extortion.

This advisory provides observed tactics and techniques, as well as indicators of compromise (IOCs) that FBI, CISA, ACSC, and NCSC assess are likely associated with this Iranian government-sponsored APT activity.

The FBI, CISA, ACSC, and NCSC urge critical infrastructure organizations to apply the recommendations listed in the Mitigations section of this advisory to mitigate risk of compromise from Iranian government-sponsored cyber actors.

For a downloadable copy of IOCs, see AA21-321A.stix.

For more information on Iranian government-sponsored malicious cyber activity, see us-cert.cisa.gov/Iran.

Click here for a PDF version of this report.

Technical Details

Threat Actor Activity

Since at least March 2021, the FBI and CISA have observed Iranian government-sponsored APT actors leverage Microsoft Exchange and Fortinet vulnerabilities to target a broad range of victims across multiple critical infrastructure sectors in furtherance of malicious activities. Observed activity includes the following.

  • In March 2021, the FBI and CISA observed these Iranian government-sponsored APT actors scanning devices on ports 4443, 8443, and 10443 for Fortinet FortiOS vulnerability CVE-2018-13379, and enumerating devices for FortiOS vulnerabilities CVE-2020-12812 and CVE-2019-5591. The Iranian Government-sponsored APT actors likely exploited these vulnerabilities to gain access to vulnerable networks. Note: for previous FBI and CISA reporting on this activity, refer to Joint Cybersecurity Advisory: APT Actors Exploit Vulnerabilities to Gain Initial Access for Future Attacks.
  • In May 2021, these Iranian government-sponsored APT actors exploited a Fortigate appliance to access a webserver hosting the domain for a U.S. municipal government. The actors likely created an account with the username elie to further enable malicious activity. Note: for previous FBI reporting on this activity, refer to FBI FLASH: APT Actors Exploiting Fortinet Vulnerabilities to Gain Initial Access for Malicious Activity.
  • In June 2021, these APT actors exploited a Fortigate appliance to access environmental control networks associated with a U.S.-based hospital specializing in healthcare for children. The Iranian government-sponsored APT actors likely leveraged a server assigned to IP addresses 91.214.124[.]143 and 162.55.137[.]20—which FBI and CISA judge are associated with Iranian government cyber activity—to further enable malicious activity against the hospital’s network. The APT actors accessed known user accounts at the hospital from IP address 154.16.192[.]70, which FBI and CISA judge is associated with government of Iran offensive cyber activity.
  • As of October 2021, these APT actors have leveraged a Microsoft Exchange ProxyShell vulnerability—CVE-2021-34473—to gain initial access to systems in advance of follow-on operations.

ACSC considers that this APT group has also used the same Microsoft Exchange vulnerability (CVE-2021-34473) in Australia.

MITRE ATT&CK Tactics and Techniques

FBI, CISA, ACSC, and NCSC assess the following tactics and techniques are associated with this activity.

Resource Development [TA0042]

The APT actors have used the following malicious and legitimate tools [T1588.001, T1588.002] for a variety of tactics across the enterprise spectrum.

  • Mimikatz for credential theft [TA0006]
  • WinPEAS for privilege escalation [TA0004]
  • SharpWMI (Windows Management Instrumentation)
  • WinRAR for archiving collected data [TA0009, T1560.001]
  • FileZilla for transferring files [TA0010]

Initial Access [TA0001]

The Iranian government-sponsored APT actors gained initial access by exploiting vulnerabilities affecting Microsoft Exchange servers (CVE-2021-34473) and Fortinet devices (CVE-2018-13379, CVE-2020-12812, and CVE-2019-5591) [T1190].

Execution [TA0002]

The Iranian government-sponsored APT actors may have made modifications to the Task Scheduler [T1053.005]. These modifications may display as unrecognized scheduled tasks or actions. Specifically, the below established tasks may be associated with this activity:

  • SynchronizeTimeZone
  • GoogleChangeManagement
  • MicrosoftOutLookUpdater
  • MicrosoftOutLookUpdateSchedule

Persistence [TA0003]

The Iranian government-sponsored APT actors may have established new user accounts on domain controllers, servers, workstations, and active directories [T1136.001, T1136.002]. Some of these accounts appear to have been created to look similar to other existing accounts on the network, so specific account names may vary per organization. In addition to unrecognized user accounts or accounts established to masquerade as existing accounts, the following account usernames may be associated with this activity:

  • Support
  • Help
  • elie
  • WADGUtilityAccount

Exfiltration [TA0010]

The FBI and CISA observed outbound File Transfer Protocol (FTP) transfers over port 443.

Impact [TA0040]

The APT actors forced BitLocker activation on host networks to encrypt data [T1486]. The corresponding threatening notes were either sent to the victim or left on the victim network as a .txt file. The ransom notes included ransom demands and the following contact information. 

  • sar_addr@protonmail[.]com
  • WeAreHere@secmail[.]pro
  • nosterrmann@mail[.]com
  • nosterrmann@protonmail[.]com 

Detection

The FBI, CISA, ACSC, and NCSC recommend that organizations using Microsoft Exchange servers and Fortinet investigate potential suspicious activity in their networks. 

  • Search for IOCs. Collect known-bad IOCs and search for them in network and host artifacts. Note: refer to Appendix A for IOCs.
  • Investigate exposed Microsoft Exchange servers (both patched and unpatched) for compromise. 
  • Investigate changes to Remote Desktop Protocol (RDP), firewall, and Windows Remote Management (WinRM) configurations that may allow attackers to maintain persistent access. 
  • Review domain controllers, servers, workstations, and active directories for new or unrecognized user accounts.
  • Review Task Scheduler for unrecognized scheduled tasks. Additionally, manually review operating-system defined or recognized scheduled tasks for unrecognized “actions” (for example, review the steps each scheduled task is expected to perform).
  • Review antivirus logs for indications they were unexpectedly turned off.
  • Look for WinRAR and FileZilla in unexpected locations. 

Note: for additional approaches on uncovering malicious cyber activity, see joint advisory Technical Approaches to Uncovering and Remediating Malicious Activity, authored by CISA and the cybersecurity authorities of Australia, Canada, New Zealand, and the United Kingdom. 

Mitigations

The FBI, CISA, ACSC, and NCSC urge network defenders to apply the following mitigations to reduce the risk of compromise by this threat.

Patch and Update Systems

  • Install updates/patch operating systems, software, and firmware as soon as updates/patches are released. 
  • Immediately patch software affected by vulnerabilities identified in this advisory: CVE-2021-34473, CVE-2018-13379, CVE-2020-12812, and CVE-2019-5591.

Evaluate and Update Blocklists and Allowlists

  • Regularly evaluate and update blocklists and allowlists.
  • If FortiOS is not used by your organization, add the key artifact files used by FortiOS to your organization’s execution blocklist. Any attempts to install or run this program and its associated files should be prevented.

Implement and Enforce Backup and Restoration Policies and Procedures

  • Regularly back up data, air gap, and password protect backup copies offline.
  • Ensure copies of critical data are not accessible for modification or deletion from the system where the data resides. 
  • Implement a recovery plan to maintain and retain multiple copies of sensitive or proprietary data and servers in a physically separate, segmented, secure location (e.g., hard drive, storage device, the cloud). 

Implement Network Segmentation

  • Implement network segmentation to restrict adversary’s lateral movement. 

Secure User Accounts

  • Audit user accounts with administrative privileges and configure access controls under the principles of least privilege and separation of duties. 
  • Require administrator credentials to install software. 

Implement Multi-Factor Authentication

  • Use multifactor authentication where possible, particularly for webmail, virtual private networks (VPNs), and accounts that access critical systems. 

Use Strong Passwords

  • Require all accounts with password logins to have strong, unique passwords.

Secure and Monitor RDP and other Potentially Risky Services

  • If you use RDP, restrict it to limit access to resources over internal networks.
  • Disable unused remote access/RDP ports.
  • Monitor remote access/RDP logs. 

Use Antivirus Programs

  • Install and regularly update antivirus and anti-malware software on all hosts. 

Secure Remote Access

  • Only use secure networks and avoid using public Wi-Fi networks. 
  • Consider installing and using a VPN for remote access.

Reduce Risk of Phishing

  • Consider adding an email banner to emails received from outside your organization.
  • Disable hyperlinks in received emails

Resources

  • For more information on Iranian government-sponsored malicious cyber activity, see us-cert.cisa.gov/Iran. 
  • For information and resources on protecting against and responding to ransomware, refer to StopRansomware.gov, a centralized, whole-of-government webpage providing ransomware resources and alerts.
  • The joint advisory from the cybersecurity authorities of Australia, Canada, New Zealand, the United Kingdom, and the United States: 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.
  • CISA offers a range of no-cost cyber hygiene services to help critical infrastructure organizations assess, identify, and reduce their exposure to threats, including ransomware. By requesting these services, organizations of any size could find ways to reduce their risk and mitigate attack vectors.
  • The U.S. Department of State’s Rewards for Justice (RFJ) program offers a reward of up to $10 million for reports of foreign government malicious activity against U.S. critical infrastructure. See the RFJ website for more information and how to report information securely.
  • ACSC can provide tailored cyber security advice and assistance, reporting, and incident response support at cyber.gov.au and via 1300 292 371 (1300 CYBER1).

Appendix A: Indicators of Compromise

IP addresses and executables files are listed below. For a downloadable copy of IOCs, see AA21-321A.stix.

IP Addresses

  • 91.214.124[.]143 
  • 162.55.137[.]20 
  • 154.16.192[.]70

Executable Files 

Executable files observed in this activity are identified in table 1.

Table 1: Executable Files 

Filename: MicrosoftOutLookUpdater[.]exe 
MD5: 1444884faed804667d8c2bfa0d63ab13
SHA-1: 95E045446EFB8C9983EBFD85E39B4BE5D92C7A2A
SHA-256: c51fe5073bd493c7e8d83365aace3f9911437a0f2ae80042ba01ea46b55d2624
SHA-512: 6451077B99C5F8ECC5C0CA88FE272156296BEB91218B39AE28A086DBA5E7E39813F044F9AF0FEDBB260941B1CD52FA237C098CBF4B2A822F08E3E98E934D0ECF
Filename: MicrosoftOutlookUpdater.bat
MD5: 1A44368EB5BF68688BA4B4357BDC874F
SHA-1 FA36FEBFD5A5CA0B3A1B19005B952683A7188A13
SHA-256 3A08D0CB0FF4D95ED0896F22F4DA8755525C243C457BA6273E08453E0E3AC4C4
SHA-512 70AA89449EB5DA1D84B70D114EF9D24CB74751CE12D12C783251E51775C89FDCE61B4265B43B1D613114D6A85E9C75927B706F39C576DBB036079C7E8CAF28B2
Filename: MicrosoftOutlookUpdater.xml
MD5: AA40C49E309959FA04B7E5AC111BB770
SHA-1 F1D90E10E6E3654654E0A677763C9767C913F8F0
SHA-256 5C818FE43F05F4773AD20E0862280B0D5C66611BB12459A08442F55F148400A6
SHA-512 E55A86159F2E869DCDB64FDC730DA893718E20D65A04071770BD32CAE75FF8C34704BDF9F72EF055A3B362759EDE3682B3883C4D9BCF87013076638664E8078E
Filename: GoogleChangeManagement.xml
MD5: AF2D86042602CBBDCC7F1E8EFA6423F9
SHA-1 CDCD97F946B78831A9B88B0A5CD785288DC603C1
SHA-256 4C691CCD811B868D1934B4B8E9ED6D5DB85EF35504F85D860E8FD84C547EBF1D
SHA-512 6473DAC67B75194DEEAEF37103BBA17936F6C16FFCD2A7345A5A46756996FAD748A97F36F8FD4BE4E1F264ECE313773CC5596099D68E71344D8135F50E5D8971
Filename: Connector3.exe
MD5: e64064f76e59dea46a0768993697ef2f
Filename: Audio.exe or frpc.exe
MD5: b90f05b5e705e0b0cb47f51b985f84db
SHA-1 5bd0690247dc1e446916800af169270f100d089b
SHA-256: 28332bdbfaeb8333dad5ada3c10819a1a015db9106d5e8a74beaaf03797511aa
Vhash: 017067555d5d15541az28!z
Authentihash: ed463da90504f3adb43ab82044cddab8922ba029511da9ad5a52b8c20bda65ee
Imphash: 93a138801d9601e4c36e6274c8b9d111
SSDEEP: 98304:MeOuFco2Aate8mjOaFEKC8KZ1F4ANWyJXf/X+g4:MeHFV2AatevjOaDC8KZ1xNWy93U
Note:

Identical to “frpc.exe” available at:

https://github[.]com/fatedier/frp/releases/download/v0.34.3/frp_0.34.3_windows_amd64.zip
Filename: Frps.exe
MD5: 26f330dadcdd717ef575aa5bfcdbe76a
SHA-1 c4160aa55d092cf916a98f3b3ee8b940f2755053
SHA-256: d7982ffe09f947e5b4237c9477af73a034114af03968e3c4ce462a029f072a5a
Vhash: 017057555d6d141az25!z
Authentihash: 40ed1568fef4c5f9d03c370b2b9b06a3d0bd32caca1850f509223b3cee2225ea
Imphash: 91802a615b3a5c4bcc05bc5f66a5b219
SSDEEP: 196608:/qTLyGAlLrOt8enYfrhkhBnfY0NIPvoOQiE:GLHiLrSfY5voO
Note:

Identical to “frps.exe” available at: 

https://github[.]com/fatedier/frp/releases/download/v0.33.0/frp_0.33.0_windows_amd64.zip

 

 

APPENDIX B: MITRE ATT&CK TACTICS AND TECHNIQUES

Table 2 identifies MITRE ATT&CK Tactics and techniques observed in this activity.

Table 2: Observed Tactics and Techniques

Tactic Technique
Resource Development [TA0042]

Obtain Capabilities: Malware [T1588.001]

Obtain Capabilities: Tool [T1588.002]
Initial Access [TA0001]

Exploit Public-Facing Application [T1190]

Execution [TA0002]

Scheduled Task/Job: Scheduled Task [T1053.005]
Persistence [TA0003]

Create Account: Local Account [T1136.001]
Create Account: Domain Account [T1136.002]
Privilege Escalation [TA0004]  

Credential Access [TA0006]

  
Collection [TA0009]

Archive Collected Data: Archive via Utility [T1560.001]
Exfiltration [TA0010]  
Impact [TA0040] Data Encrypted for Impact [T1486]

Contact Information

To report suspicious or criminal activity related to information found in this Joint Cybersecurity Advisory, contact your local FBI field office at https://www.fbi.gov/contact-us/field-offices, or the FBI’s 24/7 Cyber Watch (CyWatch) at (855) 292-3937 or by e-mail at CyWatch@fbi.gov. When available, please include the following information regarding the incident: date, time, and location of the incident; type of activity; number of people affected; type of equipment used for the activity; the name of the submitting company or organization; and a designated point of contact. To request incident response resources or technical assistance related to these threats, contact CISA at CISAServiceDesk@cisa.dhs.gov. Australian organizations can visit cyber.gov.au or call 1300 292 371 (1300 CYBER 1) to report cybersecurity incidents and access alerts and advisories.

Revisions

  • November 17, 2021: Initial Version
  • November 19, 2021: Added STIX files

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