Top 10 Malware

Summary:

For February 2022, the Top 10 stayed consistent with the previous month with the exception of Arechlient2, CryptoWall, and Delf. CryptoWall returned to the Top 10, while Arechclient2 and Delf made their first appearances. Arechclient2 is a .NET RAT with numerous capabilities, including multiple stealth functions. Arechclient2 can profile victim systems, steal information such as browser and crypto-wallet data, and launch a hidden secondary desktop to control browser sessions. Additionally, it has several anti-VM and anti-emulator capabilities. Delf is a family of malware with multiple variants written in the Delphi programming language, where most are downloaders. Campaigns, targets, infection vectors and capabilities vary based on the variant. Delf has multiple initial infection vectors, such as: dropped, malspam, or unintentional downloaded from a malicious website. Some of the abilities Delf variants exhibit include: backdoor or proxy functionality, stealing information, terminating antivirus applications, and mass mailing. The Top 10 Malware variants comprise 72 percent of the total malware activity in February 2022, increasing 3 percent from January 2022.

Additional Discussion:

Below are the Top 10 Malware ranked in order of prevalence. The respective indicators of compromise (IOCs) are provided to aid in detecting and preventing infections from these Top 10 Malware variants. Note:The associated URIs are aligned with malware’s respective domain(s) or IP(s) and increase the likelihood of maliciousness when found together. The URIs alone are not inherently malicious.

1. Shlayer
   Shlayer is a downloader and dropper for MacOS malware. It is primarily distributed through malicious websites, hijacked domains, and malvertizing posing as a fake Adobe Flash updater.
   All Shlayer domains follow the same pattern. Below are several examples of domains Shlayer uses.
   Domains
   • api[.]interfacecache[.]com
   • api[.]scalableunit[.]com
   • api[.]typicalconfig[.]com
   • api[.]standartanalog[.]com
   • api[.]fieldenumerator[.]com
   • api[.]practicalsprint[.]com
   • api[.]searchwebsvc[.]com
   • api[.]connectedtask[.]com
   • api[.]navigationbuffer[.]com
   • api[.]windowtask[.]com

2. NanoCore
   NanoCore is a RAT spread via malspam as a malicious Excel XLS spreadsheet. As a RAT, NanoCore can accept commands to download and execute files, visit websites, and add registry keys for persistence.

3. Agent Tesla
   Agent Tesla is a RAT that exfiltrate credentials, log keystrokes, and capture screenshots from an infected computer.

4. ZeuS
   ZeuS is a modular banking trojan that uses keystroke logging to compromise victim credentials when the user visits a banking website. Since the release of the ZeuS source code in 2011, many other malware variants have adopted parts of its codebase, which means that events classified as ZeuS may actually be other malware using parts of the ZeuS code.

5. Arechclient2
   Arechclient2, aka SectopRAT, is a .NET RAT with numerous capabilities, including multiple stealth functions. Arechclient2 can profile victim systems, steal information such as browser and crypto-wallet data, and launch a hidden secondary desktop to control browser sessions. Additionally, it has several anti-VM and anti-emulator capabilities.

6. Delf
   Delf is a family of malware with multiple variants written in the Delphi programming language, where most are downloaders. Campaigns, targets, infection vectors, and capabilities differ based on the variant. Delf has multiple initial infection vectors, such as: dropped, malspam, or unintentional downloaded from a malicious website. Some of the abilities Delf variants exhibit include: backdoor or proxy functionality, stealing information, terminating antivirus applications, and mass mailing.

7. Mirai
   Mirai is a malware botnet known to compromise Internet of Things (IoT) devices in order to conduct large-scale DDoS attacks. Mirai is dropped after an exploit has allowed the attacker to gain access to a machine.

8. CryptoWall
   CryptoWall is a ransomware commonly distributed through malspam with malicious ZIP attachments, Java vulnerabilities, and malicious advertisements. Upon successful infection, CryptoWall will scan the system for drive letters, network shares, and removable drives. CryptoWall runs on both 32-bit and 64-bit systems. a PowerShell-based backdoor allowing the attacker to obtain the system’s hostname and to run commands. This backdoor communicates through a DNS tunneling channel on the compromised server.

9. RedLine
   RedLine, is an infostealer available for purchase on cyber-criminal forums. Campaigns, targets, infection vectors and capabilities vary based on the version purchased. The malware typically targets information that can be easily monetized, such as credentials, cookies, banking information, and cryptocurrency wallet information. Additionally, the malware gathers information about the infected system such as web-browser, FTP clients, instant messengers, VPN services, and gaming clients. Furthermore, RedLine has remote functionality allowing it to download further malicious tools or drop additional malware.

Link:

• https://www.cisecurity.org/insights/blog/Top-10-Malware-February-2021