AlexProtectorv04beta1byAlex

Hunt Hypothesis

This rule identifies the presence of the AlexProtector v04 beta malware family, a tool often used by threat actors to establish persistence and execute payloads on compromised hosts. Proactively hunting for this signature allows the SOC to detect low-severity infections early, preventing potential lateral movement or data exfiltration within the Azure environment.

YARA Rule

rule AlexProtectorv04beta1byAlex
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 60 E8 01 00 00 00 C7 83 C4 04 33 C9 E8 01 00 00 00 68 83 C4 04 E8 01 00 00 00 68 83 C4 04 B9 ?? 00 00 00 E8 01 00 00 00 68 83 C4 04 E8 00 00 00 00 E8 01 00 00 00 C7 83 C4 04 8B 2C 24 83 C4 04 E8 01 00 00 00 A9 83 C4 04 81 ED 3C 13 40 00 E8 01 00 00 00 68 }

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

• Legacy Application Compatibility Shims: The rule may trigger on older versions of Adobe Acrobat Reader or Microsoft Office 2010 that utilize specific memory protection mechanisms or legacy DLL injection techniques to maintain compatibility with modern OS kernels.

  • Filter/Exclusion: Exclude processes where the executable path contains C:\Program Files\Adobe\Acrobat DC\ or C:\Program Files\Microsoft Office\Office14\ and the parent process is WINWORD.EXE or ACROR32.EXE.

• Endpoint Protection Agent Self-Defense: The detection might flag the CrowdStrike Falcon (FalconSensor.exe) or SentinelOne (S1Service.exe) agents when they perform internal memory scanning or integrity checks on their own driver modules, which can mimic the behavior pattern targeted by this YARA rule.

  • Filter/Exclusion: Exclude events where the process name is FalconSensor.exe or S1Service.exe and the command line contains arguments related to --self-check or --integrity-verify.

• Scheduled Database Maintenance Jobs: SQL Server Agent jobs that execute sqlcmd.exe or bcp.exe to perform database backups or index rebuilds may trigger the rule if the job involves loading specific native C++ libraries for compression or encryption that match the beta signature.

  • Filter/Exclusion: Exclude processes where the parent process is SQLAGENT.EXE and the child process is sqlcmd.exe or bcp.exe, specifically when the working directory is within the C:\Program Files\Microsoft SQL Server\ tree.

• Java Virtual Machine (JVM) Native Libraries: Applications running on the Oracle JRE (e.g., java.exe or javaw.exe) that load native libraries like `