MorphineV27Holy FatherRatter29A

Hunt Hypothesis

This YARA rule targets specific memory patterns associated with the Morphine malware family, indicating potential in-memory execution or obfuscated code segments that evade traditional disk-based scanning. Proactively hunting for these signatures in Azure Sentinel allows the SOC to identify stealthy, fileless intrusions early, reducing the dwell time of adversaries who leverage low-severity, memory-resident techniques to maintain persistence.

YARA Rule

rule MorphineV27Holy_FatherRatter29A
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 00 00 00 00 00 00 00 00 [8] 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [8] 00 00 00 00 [8] 00 00 00 00 4B 65 52 6E 45 6C 33 32 2E 64 4C 6C 00 00 47 65 74 50 72 6F 63 41 64 64 72 }

condition:
		$a0
}

Deployment Notes

This YARA rule can be deployed in the following contexts:

• Microsoft Defender for Endpoint — Custom indicators / advanced hunting
• Email Gateway — Attachment scanning
• File Share Monitoring — Periodic scanning of shared drives
• YARA CLI — Manual threat hunting on endpoints

This rule contains 1 string patterns in its detection logic.

• Source Rule

False Positive Guidance

• Legacy Java Application Deployment: When deploying older enterprise Java applications (e.g., legacy ERP modules or custom internal tools) that bundle specific versions of the Java Runtime Environment (JRE) or third-party libraries containing known byte-code patterns, the java or jre binaries may match the YARA signature.
  • Filter/Exclusion: Exclude files located in standard JRE/JDK installation directories (e.g., C:\Program Files\Java\, C:\Program Files (x86)\Java\) or specific known legacy application install paths (e.g., C:\Apps\LegacyERP\bin\).
• Scheduled Backup Agent Execution: Enterprise backup agents (such as Veeam, Commvault, or Veritas) often use helper executables or DLLs that are digitally signed but may contain specific string patterns or code structures that trigger generic YARA rules if the rule is not strictly scoped to malware families.
  • Filter/Exclusion: Exclude processes initiated by known backup service executables (e.g., vssadmin.exe, commvault\agent\bin\agent.exe) or files with a valid digital signature from a trusted publisher (e.g., “Veeam Software”, “Commvault Systems”) located in the backup agent’s installation directory.
• Development Toolchain Compilation: During CI/CD pipeline builds or local developer workstations, tools like Maven, Gradle, or Ant may generate temporary JAR files or native libraries that contain specific bytecode sequences or string constants (e.g., “HolyFather”, “Ratter”) used in internal project names or library identifiers.
  • Filter/Exclusion: Exclude files in temporary build directories (e.g., C:\Users\<user>\.m2\repository\, C:\Users\<user>\.gradle\caches\) or files created within the last 24