yodasProtector102AshkibizDanehlar

Hunt Hypothesis

This hypothesis targets the execution of the YodasProtector malware family, a known threat that often leverages specific memory patterns or code structures to establish persistence or perform data exfiltration. Proactively hunting for this signature in Azure Sentinel allows the SOC to identify compromised endpoints early, preventing potential lateral movement or privilege escalation before the low-severity indicator escalates into a more impactful breach.

YARA Rule

rule yodasProtector102AshkibizDanehlar
{
      meta:
		author="malware-lu"
strings:
		$a0 = { E8 03 00 00 00 EB 01 ?? BB 55 00 00 00 E8 03 00 00 00 EB 01 ?? E8 8F 00 00 00 E8 03 00 00 00 EB 01 ?? E8 82 00 00 00 E8 03 00 00 00 EB 01 ?? E8 B8 00 00 00 E8 03 00 00 00 EB 01 ?? E8 AB 00 00 00 E8 03 00 00 00 EB 01 ?? 83 FB 55 E8 03 00 00 00 EB 01 ?? 75 }

condition:
		$a0 at pe.entry_point
}

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

• Scenario: A developer or DevOps engineer uses a custom-built internal tool or a specific version of a build automation script (e.g., a Python wrapper around MSBuild or a custom Go binary) that includes specific string constants or byte sequences matching the yodasProtector102 signature due to shared library linking or hardcoded configuration strings.
  • Filter/Exclusion: Exclude files located in standard development directories (e.g., C:\Users\*\AppData\Local\Temp, C:\Projects\, C:\BuildAgents\) and exclude processes initiated by known build service accounts (e.g., svc-build, jenkins-agent).
• Scenario: An enterprise endpoint protection agent (such as CrowdStrike Falcon, Carbon Black, or SentinelOne) performs a real-time scan or quarantine action on a newly downloaded installer or update package that contains the specific byte pattern, triggering the YARA rule during the scan process before the file is fully written or executed.
  • Filter/Exclusion: Exclude events where the parent process is a known EDR service executable (e.g., FalconSensor.exe, cb.exe, sentinelone.exe) and the file path resides in the EDR’s temporary scan directory (e.g., C:\ProgramData\CrowdStrike\, C:\ProgramData\CarbonBlack\).
• Scenario: A scheduled maintenance job (e.g., a PowerShell script running via Task Scheduler) downloads and executes a legitimate vendor-provided diagnostic tool or log collector (e.g., vcredist_x64.exe from a specific vendor or a custom logcollector.exe) that was compiled with a linker or compression algorithm that inadvertently matches the YARA signature.
  • Filter/Exclusion: Exclude files whose name matches known vendor tool patterns (e.g., *collector*.exe, `diag.