PROTECTEXECOMv60

Hunt Hypothesis

This detection identifies potential malicious executable behavior by leveraging a specific YARA signature (PROTECTEXECOMv60) to flag known threat patterns within file processes. A proactive hunt is essential in Azure Sentinel to uncover early-stage compromises that may evade standard alerts due to the rule’s low severity, ensuring timely identification of stealthy adversary activities before they escalate.

YARA Rule

rule PROTECTEXECOMv60
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 1E B4 30 CD 21 3C 02 73 ?? CD 20 BE [2] E8 }

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

False Positive Scenarios for Rule: PROTECTEXECOMv60

• Scenario: Microsoft Office 365 Click-to-Run Updates

  • Context: The Office Click-to-Run service (OfficeClickToRun.exe) frequently spawns child processes to apply feature updates or repair installations, which often match the YARA signature for executable protection mechanisms.
  • Filter/Exclusion: Exclude processes where the parent image is C:\Program Files\Microsoft Office Client\OfficeClickToRun.exe and the command line contains /update or /repair.

• Scenario: Scheduled Antivirus Definition Updates (CrowdStrike Falcon)

  • Context: The CrowdStrike Falcon sensor (csfalcon.exe) periodically executes its own update agents to download and install new definition signatures, triggering the rule due to the creation of temporary executable artifacts in the protected directory.
  • Filter/Exclusion: Create a filter for processes with image path C:\ProgramData\CrowdStrike\csfalcon.exe where the process name contains UpdateService or is running under the context of the “System” account during scheduled maintenance windows (e.g., 02:00–04:00).

• Scenario: Windows Defender Scheduled Scan Execution

  • Context: During a full system scan, MpCmdRun.exe invokes specific protection modules that instantiate temporary executables to verify file integrity, which can be flagged as new protected executions by the rule.
  • Filter/Exclusion: Exclude events where the parent process is C:\Program Files\Windows Defender\MpCmdRun.exe and the target path resides within the C:\ProgramData\Microsoft\Windows Defender\Platform directory.

• Scenario: SCCM (Configuration Manager) Software Deployment

  • Context: When deploying new