D1S1Gv11betaD1N

Hunt Hypothesis

This YARA rule targets specific low-severity indicators associated with the D1S1Gv11betaD1N signature, likely identifying benign or legacy software artifacts that may be misclassified as malicious or used as a low-noise foothold by adversaries. Proactively hunting for these patterns in Azure Sentinel helps the SOC team distinguish between expected low-fidelity noise and potential stealthy persistence mechanisms, ensuring that minor anomalies are not overlooked during broader threat investigations.

YARA Rule

rule D1S1Gv11betaD1N
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 00 00 00 00 [4] 00 00 00 00 00 00 01 00 0A 00 00 00 18 00 00 80 00 00 00 00 [4] 00 00 00 00 02 00 00 00 88 00 00 80 38 00 00 80 96 00 00 80 50 00 00 80 00 00 00 00 [4] 00 00 00 00 00 00 01 00 00 00 00 00 68 00 00 00 00 00 00 00 [4] 00 00 00 00 00 00 01 00 00 00 00 00 78 00 00 00 B0 [2] 00 10 00 00 00 00 00 00 00 00 00 00 00 C0 [4] 00 00 00 00 00 00 00 00 00 00 00 06 00 44 00 56 00 43 00 4C 00 41 00 4C 00 0B 00 50 00 41 00 43 00 4B 00 41 00 47 00 45 00 49 00 4E 00 46 00 4F 00 00 00 }

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

• Scenario: A developer or DevOps engineer runs a local build pipeline or CI/CD agent (e.g., Jenkins, GitLab Runner, or Azure DevOps Agent) that compiles a C/C++ project using the clang or gcc compiler. The resulting binary or intermediate object files may contain specific string patterns or structural artifacts that match the YARA signature, particularly if the rule targets common library headers or debug symbols.
  • Filter/Exclusion: Exclude processes where the parent process is a known build tool (e.g., msbuild.exe, dotnet.exe, npm.exe, make.exe) or where the file path resides in standard development directories like C:\Users\<user>\source\ or D:\builds\.
• Scenario: An enterprise endpoint protection agent (e.g., CrowdStrike Falcon, Carbon Black, or Microsoft Defender for Endpoint) performs a real-time scan or on-demand full-disk scan. During the scan, the agent reads executable files from disk into memory for analysis. If the YARA rule is applied to the memory image or the file content during this read operation, legitimate applications with specific version strings or embedded resources may trigger a match.
  • Filter/Exclusion: Exclude detections where the scanning process is a known EDR agent (e.g., FalconSensor.exe, cb.exe, MsMpEng.exe) and the target file is located in standard program directories (C:\Program Files\, C:\Program Files (x86)\).
• Scenario: A system administrator performs a scheduled Windows Update or patches a third-party application (e.g., Adobe Acrobat, Java, or .NET Framework) using a service like wuauserv (Windows Update) or a vendor-specific updater (e.g., AdobeUpdateService.exe). The updater extracts new binaries or replaces existing ones, and the temporary files