This rule detects the presence of the CERBERUSv20 malware family, which is often associated with ransomware operations or cryptominer deployments that compromise host integrity. Proactively hunting for this signature allows the SOC to identify compromised endpoints early, potentially preventing lateral movement or data exfiltration before the malware fully executes its payload.
rule CERBERUSv20
{
meta:
author="malware-lu"
strings:
$a0 = { 9C 2B ED 8C [2] 8C [2] FA E4 ?? 88 [2] 16 07 BF [2] 8E DD 9B F5 B9 [2] FC F3 A5 }
condition:
$a0 at pe.entry_point
}This YARA rule can be deployed in the following contexts:
This rule contains 1 string patterns in its detection logic.
Windows Defender Update Service Execution: The MsMpEng.exe process (Microsoft Antimalware Service Executable) is frequently launched by the Windows Update service or scheduled tasks to perform real-time protection scans or definition updates. Since this process often resides in C:\Program Files\Windows Defender\ and interacts with system files, it can trigger generic YARA rules looking for specific memory patterns or file headers associated with security tools.
MsMpEng.exe and its parent process svchost.exe when the command line arguments contain /Scan or /Update, or exclude the specific path C:\Program Files\Windows Defender\ from the file-based detection logic.Visual Studio Code Extension Host: The extensionHost.exe process from VS Code (or similar IDEs like JetBrains) loads numerous native Node.js modules and extensions (e.g., C/C++ IntelliSense, Python linters) that may contain compiled binaries or memory segments matching common YARA signatures for development tools or specific library versions.
extensionHost.exe or node.exe when the parent process is Code.exe or idea64.exe, and restrict the exclusion to paths under C:\Users\<User>\AppData\Local\Programs\Microsoft VS Code\ or equivalent IDE installation directories.Java Web Start or JRE Background Tasks: Processes like javaw.exe or java.exe are often used for background services (e.g., Oracle Java Control Panel, Adobe AIR apps, or enterprise Java applications). These JVMs load native libraries (.dll or .so files) that may contain specific byte sequences or version strings that match YARA rules targeting known Java-based malware or specific library versions.