RLPV073betaap0x

Hunt Hypothesis

This detection identifies potential file-based threats matching the specific signature pattern of the RLPV073betaap0x YARA rule within Azure Sentinel’s endpoint telemetry. A proactive hunt is recommended to uncover early-stage or low-severity indicators that may represent novel adversary activity before they escalate into significant incidents.

YARA Rule

rule RLPV073betaap0x
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 2E 72 6C 70 00 00 00 00 00 50 00 00 [12] 00 00 00 00 00 00 00 00 00 00 00 00 20 00 00 E0 }

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

Here are 4 specific false positive scenarios for the detection rule RLPV073betaap0x, along with recommended filters and exclusions:

• Scenario: Microsoft Defender Antivirus Cloud-Connected Protection Updates

  • Context: The YARA rule likely flags the MsMpEng.exe process when it downloads or applies heuristic updates from the cloud. This often involves creating temporary files in %ProgramData%\Microsoft\Windows Defender\Updates that match the signature pattern of the rule.
  • Filter/Exclusion: Add an exclusion for the executable path C:\Program Files\Microsoft Defender Antivirus\msmpeng.exe. Additionally, filter out events where the parent process is MsMpEng.exe and the file extension is .cab or .dat located within the Windows Defender updates directory.

• Scenario: Scheduled System Backup via Veeam Agent

  • Context: During nightly maintenance windows (e.g., 02:00 AM), the Veeam Agent for Windows (VeeamService.exe) creates temporary staging files and compression archives in the C:\ProgramData\Veeam\Backup directory. These operations often trigger file creation events that mimic the behavioral pattern of the RLPV073betaap0x rule.
  • Filter/Exclusion: Create a time-based exclusion for the user account NT SERVICE\VeeamTransportService between 01:00 and 05:00 daily. Alternatively, exclude file paths matching C:\ProgramData\Veeam\Backup\* from the rule’s scope.

• Scenario: Enterprise Software Deployment via SCCM/Intune

  • Context: When System Center Configuration Manager (SCCM) or Microsoft Intune pushes a new application package to endpoints, the client service (ccmexec.exe) extracts installation binaries