Enfal

Hunt Hypothesis

The Enfal rule detects potential adversary behavior involving unusual command and control communication patterns that may indicate covert data exfiltration or persistent access. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify and mitigate early-stage threats that evade traditional detection methods.

YARA Rule

rule Enfal : Family
{
    meta:
        description = "Enfal"
        author = "Seth Hardy"
        last_modified = "2014-06-19"
        
    condition:
        EnfalCode or EnfalStrings
}

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
• Source Rule

False Positive Guidance

• Scenario: System backup process using Veeam Backup & Replication
  Filter/Exclusion: process.name != "vbm" or process.name != "vbackup"

• Scenario: Scheduled system maintenance task using Task Scheduler
  Filter/Exclusion: process.name != "schtasks" or process.name != "taskhost"

• Scenario: Log file rotation using Logrotate on Linux systems
  Filter/Exclusion: process.name != "logrotate" or process.name != "sh" AND process.name != "bash"

• Scenario: Admin performing disk cleanup using Disk Cleanup (Windows)
  Filter/Exclusion: process.name != "cleanmgr.exe" or process.name != "dlm"

• Scenario: Database maintenance job using SQL Server Agent
  Filter/Exclusion: process.name != "sqlagent.exe" or process.name != "sqlservr"