UnoPiX075BaGiE

Hunt Hypothesis

This YARA rule targets specific memory patterns or code artifacts associated with the UnoPiX075BaGiE signature, potentially indicating the presence of a low-severity implant or obfuscated payload in process memory. Proactively hunting for this signature allows the SOC team to identify stealthy, low-noise adversary footholds that may evade traditional network-based detections, ensuring early discovery of persistent or dormant threats within the Azure Sentinel environment.

YARA Rule

rule UnoPiX075BaGiE
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 60 E8 07 00 00 00 61 68 [2] 40 00 C3 83 04 24 18 C3 20 83 B8 ED 20 37 EF C6 B9 79 37 9E 61 }

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

• Legacy Application Deployment via Group Policy: The YARA rule likely targets specific byte patterns or string signatures common in older, unmanaged legacy applications (e.g., custom-built internal tools or old versions of Adobe Reader/Java) that are deployed to endpoints via Group Policy Objects (GPO). These binaries often reside in C:\Program Files\ or C:\Windows\System32\ and are executed by the gpupdate or svchost processes during policy refresh cycles.

  • Filter/Exclusion: Exclude alerts where the parent process is gpupdate.exe or svchost.exe (specifically the gpupdate service) and the file path matches C:\Program Files\ or C:\Windows\System32\.

• Scheduled Backup or Maintenance Jobs: Certain enterprise backup agents (e.g., Veeam, Commvault) or maintenance scripts (e.g., disk cleanup, log rotation) may use temporary executable wrappers or specific binary signatures that match the YARA rule’s pattern. These jobs are typically triggered by Task Scheduler (taskschd.msi or schtasks.exe) and run under the SYSTEM or a dedicated service account.

  • Filter/Exclusion: Exclude alerts where the parent process is taskschd.msi or schtasks.exe and the user context is SYSTEM or a known service account (e.g., BackupSvc, MaintenanceAdmin).

• Software Update Mechanisms: Major enterprise software suites (e.g., Microsoft Office, SAP, Oracle) use update agents that download and execute new binaries. These update executables may contain specific version strings or code segments that trigger the YARA rule. The parent process is often the application’s updater service (e.g., OfficeClickToRun.exe, sapupdatemanager.exe).

  • **Filter/