This rule detects the presence of MoleBox, a lightweight Windows sandboxing tool frequently used by adversaries to isolate malicious payloads and evade host-based security controls. Proactively hunting for this artifact in Azure Sentinel allows the SOC to identify potential staging or execution environments that may be hiding advanced malware or exploit development activities from standard detection mechanisms.
rule MoleBoxv20
{
meta:
author="malware-lu"
strings:
$a0 = { E8 [4] 60 E8 4F }
condition:
$a0
}This YARA rule can be deployed in the following contexts:
This rule contains 1 string patterns in its detection logic.
Antivirus/EDR Signature Update Scans: When endpoint protection agents (e.g., CrowdStrike Falcon, Microsoft Defender for Endpoint) perform full-disk or heuristic scans, they may temporarily load or map YARA rule files (including MoleBoxv20) into memory or create short-lived temporary files in C:\ProgramData or C:\Windows\Temp.
FalconSensor.exe, MsMpEng.exe, Defender.exe) or exclude file paths under standard AV update directories (e.g., C:\ProgramData\Microsoft\Windows Defender\, C:\ProgramData\CrowdStrike\).Security Tooling and Threat Hunting Scripts: During proactive threat hunting or incident response, analysts often use tools like yara64.exe, SigmaHQ converters, or custom PowerShell/Bash scripts to test YARA rules against live memory dumps or file systems. This can trigger the rule if the rule file itself is being parsed or if a test binary is created.
powershell.exe, cmd.exe, yara64.exe, python.exe) and the file path resides in user-specific directories (e.g., C:\Users\<User>\Documents\, C:\Tools\).CI/CD Pipeline Artifact Staging: In DevOps environments, security scanning jobs (e.g., in Azure DevOps, Jenkins, or GitLab CI) may download or stage YARA rule files as part of a build artifact or container image layer. These files are often stored in temporary workspace directories during the build process.