RLP 073beta ap0x h

Hunt Hypothesis

This YARA rule targets the RLP 073beta ap0x h signature, which likely identifies specific malicious payloads or obfuscated code patterns associated with low-severity threats or known exploit kits. Proactively hunting for this signature in Azure Sentinel allows the SOC team to detect subtle or early-stage intrusions that may not yet trigger high-fidelity alerts, ensuring timely identification of potential footholds within the environment.

YARA Rule

rule RLP_073beta_ap0x_h: PEiD
{
    strings:
        $a = { 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 ?? ?? 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:
        $a 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

• Legacy Application Patching via Silent Installers: Enterprise IT often deploys updates for legacy software (e.g., older versions of Adobe Acrobat, Java, or specialized engineering tools like MATLAB) using silent installers. These installers frequently bundle temporary executables or self-extracting archives that may match the RLP_073beta_ap0x_h signature if the rule targets specific binary patterns or strings associated with older build artifacts.

  • Filter/Exclusion: Exclude processes initiated by known patch management agents (e.g., wsus, ccmexec.exe for SCCM, or wsus service) or specific vendor installer paths (e.g., C:\Program Files\Adobe\Acrobat DC\AcroUpdate.exe) when the parent process is a recognized service or admin tool.

• Virtual Machine Snapshot or Backup Operations: During backup or snapshot operations (e.g., using Veeam, Commvault, or Windows Server Backup), hypervisors or backup agents may create temporary disk image files or mount virtual disks. If the YARA rule scans memory or file headers of mounted images, it might flag legitimate virtual disk metadata or embedded OS components that resemble the target pattern.

  • Filter/Exclusion: Exclude alerts where the file path resides in known backup directories (e.g., C:\ProgramData\Veeam\Backup\, D:\Backups\) or where the parent process is a backup agent (vbr.exe, commvault\sim.exe) and the action is a read/mount operation rather than execution.

• Development Environment Build Artifacts: In software development environments, build tools (e.g., MSBuild, CMake, or Gradle) generate intermediate object files, debug symbols, or temporary executables in build directories. If the RLP_073beta_ap0x_h rule matches specific compiler-generated code