Detects svcstat from Regin report - file svcsstat.exe_sample

Hunt Hypothesis

The hypothesis is that the presence of svcsstat.exe_sample may indicate the execution of Regin malware, which is used for command and control communication. SOC teams should proactively hunt for this behavior in Azure Sentinel to identify potential long-term persistence and C2 activity associated with advanced persistent threats.

YARA Rule

rule Regin_sig_svcsstat 
{

    meta:
        description = "Detects svcstat from Regin report - file svcsstat.exe_sample"
        author = "@MalwrSignatures"
        date = "26.11.14"
        hash = "5164edc1d54f10b7cb00a266a1b52c623ab005e2"

    strings:
        $s0 = "Service Control Manager" fullword ascii
        $s1 = "_vsnwprintf" fullword ascii
        $s2 = "Root Agency" fullword ascii
        $s3 = "Root Agency0" fullword ascii
        $s4 = "StartServiceCtrlDispatcherA" fullword ascii
        $s5 = "\\\\?\\UNC" fullword wide
        $s6 = "%ls%ls" fullword wide

    condition:
        all of them and filesize < 15KB and filesize > 10KB 
}

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 7 string patterns in its detection logic.

• Source Rule

False Positive Guidance

• Scenario: A system administrator is using svcsstat.exe as part of a Microsoft System Center Configuration Manager (SCCM) health check or reporting task.
  Filter/Exclusion: Check for the presence of SCCM or Configuration Manager in the process command line or parent process tree.

• Scenario: A Windows Update Agent or Windows Server Update Services (WSUS) component is running svcsstat.exe to collect service status for update tracking.
  Filter/Exclusion: Filter by process parent process names like wuauserv.exe or wsusserver.exe.

• Scenario: A scheduled task is configured to run svcsstat.exe as part of a Microsoft Endpoint Manager (MEM) or Intune health monitoring routine.
  Filter/Exclusion: Exclude processes launched by scheduled tasks with names like TaskScheduler or schtasks.exe.

• Scenario: A third-party monitoring tool such as PRTG Network Monitor or Nagios is using svcsstat.exe to gather service status metrics.
  Filter/Exclusion: Check for known monitoring tool process names or command-line arguments associated with those tools.

• Scenario: A custom PowerShell script or Windows Task Scheduler job is using svcsstat.exe to gather service status for internal reporting or auditing.
  Filter/Exclusion: Filter based on the presence of PowerShell.exe or TaskScheduler in the parent process chain, and check for known internal script paths.