SmokesCryptv12 | SOC Hunt Feed

Hunt Hypothesis

This rule detects the presence of the SmokesCrypt v12 malware family, a known cryptor often used in ransomware attacks to encrypt files and lock user access. Proactively hunting for this signature in Azure Sentinel allows the SOC team to identify compromised endpoints early, potentially isolating affected systems before the encryption process completes and data is exfiltrated.

YARA Rule

rule SmokesCryptv12
{
      meta:
		author="malware-lu"
strings:
		$a0 = { 60 B8 [4] B8 [4] 8A 14 08 80 F2 ?? 88 14 08 41 83 F9 ?? 75 F1 }

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

Scenario: A developer or DevOps engineer runs the smokecrypt CLI tool locally to encrypt sensitive configuration files (e.g., .env, secrets.yaml) before committing them to a private repository or pushing them to a CI/CD pipeline.
- Filter/Exclusion: Exclude processes where the parent process is a known development tool (e.g., code.exe, idea64.exe, vscode-server) or where the command line arguments contain encrypt or --input and the working directory is within a standard source code path (e.g., C:\src\, /home/user/project/).
Scenario: An automated backup or archival job uses smokecrypt as part of a pre-backup encryption step to ensure data at rest is protected before being transferred to an off-site storage location (e.g., AWS S3, Azure Blob).
- Filter/Exclusion: Exclude executions where the parent process is a scheduled task runner (e.g., schtasks.exe, cron, systemd-run) or a backup agent (e.g., VeeamAgent.exe, BackupExec.exe) and the output path points to a known backup share or cloud storage mount point.
Scenario: A security team performs a periodic key rotation or re-encryption audit, running smokecrypt in batch mode to re-encrypt existing encrypted artifacts with a new key, often triggered by a PowerShell script or Python automation.
- Filter/Exclusion: Exclude processes where the parent is a scripting interpreter (powershell.exe, python.exe, bash.exe) and the command line includes flags for batch processing (e.g., --batch, --re-encrypt) or where the user account belongs to a specific security service group (e.g., SEC-KEY-ROTATION).
**Scenario