Morphinev27Holy FatherRatter29A

Hunt Hypothesis

This detection identifies specific file artifacts matching the “Morphinev27Holy FatherRatter29A” signature, which may indicate early-stage malware or benign software activity within the environment. Proactively hunting for this pattern in Azure Sentinel allows the SOC team to validate false positives and uncover potential low-severity threats that could serve as indicators of compromise before they escalate into critical incidents.

YARA Rule

rule Morphinev27Holy_FatherRatter29A
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 00 00 00 00 6B 65 72 6E 65 6C 33 32 2E 64 6C 6C 00 00 47 65 74 50 72 6F 63 41 64 64 72 65 73 73 00 00 4C 6F 61 64 4C 69 62 72 61 72 79 41 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 }
	$a1 = { 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 6B 65 72 6E 65 6C 33 32 2E 64 6C 6C 00 00 47 65 74 50 72 6F 63 }

condition:
		$a0 or $a1
}

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 2 string patterns in its detection logic.

• Source Rule

False Positive Guidance

Here are 4 specific false positive scenarios for the Morphinev27Holy FatherRatter29A detection rule, including suggested filters and exclusions tailored for an enterprise environment:

• Scenario: Enterprise Antivirus Real-Time Scanning

  • Context: The YARA signature may match the executable behavior or string patterns of major endpoint protection agents (e.g., Microsoft Defender, CrowdStrike Falcon) when they perform real-time file integrity checks on system directories.
  • Filter/Exclusion: Exclude processes where ProcessName is MsMpEng.exe, Cfsensr64.exe, or csfalcon.exe running under the SYSTEM account. Add a rule condition to ignore alerts if the parent process is an AV service and the file path resides within C:\Program Files\Microsoft Defender\ or C:\ProgramData\CrowdStrike\.

• Scenario: Scheduled Backup and Patching Jobs

  • Context: Automated maintenance tasks, such as Veeam backup agents or WSUS (Windows Server Update Services) deployment scripts, often execute temporary binaries that trigger the rule’s pattern matching during peak maintenance windows.
  • Filter/Exclusion: Create a time-based exclusion for alerts occurring between 02:00 and 06:00 local time on weekdays where the ProcessName matches backup agents like vrb.exe (Veeam) or usoc.dll (Windows Update). Alternatively, exclude file paths containing \Backup\, \WSUSContent\, or \Temp\Maintenance\.

• Scenario: Legacy Line-of-Business Application Updates

  • Context: Internal legacy applications (e.g., custom ERP modules or financial reporting tools) often use older runtime libraries that contain byte sequences matching the “Holy Father” signature, particularly during auto-update routines initiated by