Windows: Uncommon Child Processes Spawned by sigverif.exe

ATT&CK techniques

Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
- T1216System Script Proxy Execution
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags process creation events where sigverif.exe spawns a child process that is not one of the explicitly excluded WerFault.exe paths. Attackers may abuse sigverif.exe to blend in with legitimate activity while proxying execution to other binaries. The detection relies on Windows process creation telemetry, matching the parent image ending in \sigverif.exe and filtering out WerFault.exe child processes.

Reporting behind it

Related detections9 linkedT1216 — drag to rearrange

Suspicious PowerShell Execution via SyncAppvPublishingServer LOLBIN

PowerShell Proxy Execution via SyncAppvPublishingServer (via process_creation)

Malicious Command Injection via SyncAppvPublishingServer VBS LOLBin (via process_creation)

Suspicious winrm.vbs LOLBAS Script Execution for Code Proxying

Windows: Code execution via Pester.bat invoked by PowerShell (Invoke-Pester/Get-Help)

Windows: Suspicious CustomShellHost.exe execution spawned by non-Explorer parent

PowerShell: Signed UtilityFunctions.ps1 Loading Managed DLL via Proxy Execution

Windows PowerShell Script Proxy Execution via CL_mutexverifiers.ps1

PowerShell Assembly Loading via CL_LoadAssembly.ps1 Functions

Windows: Uncommon Child Processes Spawned by sigverif.exe

Pivot detection · T1216 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.

windows-uncommon-child-processes-spawned-by-sigverif-exe-7d4aaec2

title: "Windows: Uncommon Child Processes Spawned by sigverif.exe"
id: 2a339e7e-aec7-4ec5-86bc-3e974e8b392d
status: test
description: This rule flags process creation events where sigverif.exe spawns a child process that is not one of the explicitly excluded WerFault.exe paths. Attackers may abuse sigverif.exe to blend in with legitimate activity while proxying execution to other binaries. The detection relies on Windows process creation telemetry, matching the parent image ending in \sigverif.exe and filtering out WerFault.exe child processes.
references:
  - https://www.hexacorn.com/blog/2018/04/27/i-shot-the-sigverif-exe-the-gui-based-lolbin/
  - https://twitter.com/0gtweet/status/1457676633809330184
  - https://github.com/SigmaHQ/sigma/blob/master/rules/windows/process_creation/proc_creation_win_sigverif_uncommon_child_process.yml
author: Nasreddine Bencherchali (Nextron Systems), Huntrule Team
date: 2022-08-19
modified: 2024-08-27
tags:
  - attack.stealth
  - attack.t1216
logsource:
  category: process_creation
  product: windows
detection:
  selection:
    ParentImage|endswith: \sigverif.exe
  filter_main_werfault:
    Image:
      - C:\Windows\System32\WerFault.exe
      - C:\Windows\SysWOW64\WerFault.exe
  condition: selection and not 1 of filter_main_*
falsepositives:
  - Unknown
level: medium
license: DRL-1.1
related:
  - id: 7d4aaec2-08ed-4430-8b96-28420e030e04
    type: derived

Convert

This rule as a query you can run. Uses no unlock credit.

SplunkSPL