RLPv073betaap0x

Hunt Hypothesis

This detection identifies potential low-severity file artifacts matching the specific signature of the RLPv073betaap0x YARA rule, which may indicate early-stage adversary activity or benign application behavior within the environment. A proactive hunt is recommended to validate these occurrences against known good baselines in Azure Sentinel, ensuring that subtle indicators are not overlooked before they evolve into more significant threats.

YARA Rule

rule RLPv073betaap0x
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 60 8B DD E8 00 00 00 00 5D 95 32 C0 95 89 9D 80 00 00 00 B8 42 31 40 00 BB 41 30 40 00 2B C3 03 C5 33 D2 8A 10 40 B9 [2] 00 00 8B F9 30 10 8A 10 40 49 75 F8 64 EF 86 3D 30 00 00 0F B9 FF 4B 89 52 5C 4C BD 77 C2 0C CE 88 4E 2D E8 00 00 00 5D 0D DB 5E 56 }

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 5 specific false positive scenarios for the RLPv073betaap0x detection rule, including suggested filters and exclusions tailored for an enterprise environment:

• Scenario: Microsoft Office Click-to-Run Background Updates

  • Context: The OfficeClickToRun.exe process frequently spawns child processes (e.g., SetupController.exe) to perform background updates or repair tasks. These processes often load specific DLLs that match the YARA signature pattern, triggering alerts during peak business hours when users are actively using Office suites.
  • Suggested Filter/Exclusion: Exclude the process path C:\Program Files\Microsoft Office Root\Office16\* and specifically filter out child processes spawned by SetupController.exe where the parent image hash matches the known Microsoft-signed Office Click-to-Run installer.

• Scenario: Scheduled Antivirus Definition Updates (CrowdStrike or SentinelOne)

  • Context: Endpoint Detection and Response (EDR) agents like CrowdStrike Falcon or SentinelOne execute scheduled jobs to fetch new definition signatures. During this process, the agent’s updater service often extracts temporary archives containing executable blobs that mimic the behavior of the rule’s target logic.
  • Suggested Filter/Exclusion: Create a whitelist exclusion for processes named C:\ProgramData\CrowdStrike\fs_qr.exe (or equivalent SentinelOne paths) running under the SYSTEM account, specifically when the process command line contains keywords like “update”, “download”, or “scan”.

• Scenario: Enterprise Patch Management Deployment (SCCM/Intune)

  • Context: During scheduled maintenance windows, System Center Configuration Manager (SCCM) or Microsoft Intune deploys patches via ccmsetup.exe or WindowsUpdateAgent. These tools often extract installation packages to the C:\Windows\SoftwareDistribution folder