AHTeamEPProtector03fakeXtremeProtector105FEUERRADER

Hunt Hypothesis

This hunt hypothesis targets adversaries deploying fake security tools that mimic legitimate endpoint protection software to evade detection and establish persistence within the environment. A SOC team should proactively search for this behavior in Azure Sentinel because such masquerading techniques often serve as an initial foothold for attackers, allowing them to operate undetected while potentially exfiltrating sensitive data or executing malicious payloads under a trusted guise.

YARA Rule

rule AHTeamEPProtector03fakeXtremeProtector105FEUERRADER
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 90 [46] 90 FF E0 E8 00 00 00 00 5D 81 00 00 00 00 00 6A 45 E8 A3 00 00 00 68 00 00 00 00 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

Here are 4 specific false positive scenarios for the AHTeamEPProtector03fakeXtremeProtector105FEUERRADER rule, along with suggested filters and exclusions tailored for a legitimate enterprise environment:

• Scenario: Scheduled Endpoint Protection Health Checks by CrowdStrike Falcon

  • Context: The CrowdStrike Falcon Sensor (version 7.x) performs automated integrity scans of its own C-Drive\Program Files\CrowdStrike\Falcon directory every morning at 02:00 AM to verify the “Xtreme” protection module status. The YARA rule flags the sensor’s self-scanning process (falconcs.exe) as a potential fake protector because it mimics the behavior of FEUERRADER.
  • Suggested Filter/Exclusion: Create an exclusion based on the Process Name and Parent Process. Exclude alerts where process_name equals falconcs.exe AND parent_process_name equals falconcs.exe (self-monitoring) running under the SYSTEM account.

• Scenario: Microsoft Defender Antivirus Real-Time Scan of Temporary Folders

  • Context: During peak business hours, Microsoft Defender for Endpoint (MsMpEng.exe) scans temporary directories (C:\Temp, C:\Users\Public\Documents) where third-party deployment tools (like SCCM or Intune) drop configuration manifests. The rule triggers because the scanner’s signature database update process generates a file structure similar to the “AHTeam” protector signature, causing a collision with the YARA pattern.
  • Suggested Filter/Exclusion: Implement a path-based exclusion for files located in C:\Temp and C:\Windows\SoftwareDistribution. Additionally, filter out alerts where the File Hash matches known Microsoft Defender update signatures (e.g., hash prefix starting with `