Windows Process Creation: Suspicious cmd.exe or PowerShell Child of WSUS (wsusservice.exe)

Alerts when WSUS/IIS service processes spawn cmd or PowerShell interpreters, indicating potential exploitation and post-exploitation activity.

FreeReviewedSigma · High · v5

Product: windows
Category: process_creation
Author: Huntress Labs, Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ), DRL 1.1
Published: 2025-10-31
Updated: 2026-07-31

Analysis Detection

ATT&CK techniques

Initial Access → Execution

Recon
Resource Dev
Initial Access
- T1190Exploit Public-Facing Application
Execution
- T1203Exploitation for Client Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule flags process creation where cmd.exe or PowerShell-related interpreters (powershell.exe, pwsh.exe, powershell_ise.exe) run as child processes of WSUS components, specifically wsusservice.exe or w3wp.exe hosting the WsusPool. Spawning command-line interpreters from WSUS-related processes is a strong indicator of possible exploitation and follow-on activity because it enables shell-based execution for reconnaissance and post-exploitation. The detection relies on Windows process creation telemetry including parent image/command line and child executable paths.

Reporting behind it

Related detections9 linkedT1190 — drag to rearrange

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Windows Process Creation: Suspicious cmd.exe or PowerShell Child of WSUS (wsusservice.exe)

Pivot detection · T1190 · 9 related

Changelog

v5
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
v1
No changelog recorded for this version.2026-07-30

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

suspicious-cmd-exe-and-powershell-child-processes-of-wsus-wsusservice-exe-on-win-43259cc4

title: "Windows Process Creation: Suspicious cmd.exe or PowerShell Child of WSUS (wsusservice.exe)"
id: 3ad97575-b144-4063-a0ef-7808657dd89f
status: experimental
description: This rule flags process creation where cmd.exe or PowerShell-related interpreters (powershell.exe, pwsh.exe, powershell_ise.exe) run as child processes of WSUS components, specifically wsusservice.exe or w3wp.exe hosting the WsusPool. Spawning command-line interpreters from WSUS-related processes is a strong indicator of possible exploitation and follow-on activity because it enables shell-based execution for reconnaissance and post-exploitation. The detection relies on Windows process creation telemetry including parent image/command line and child executable paths.
references:
  - https://unit42.paloaltonetworks.com/microsoft-cve-2025-59287/
  - https://www.huntress.com/blog/exploitation-of-windows-server-update-services-remote-code-execution-vulnerability
  - https://hawktrace.com/blog/CVE-2025-59287-UNAUTH
  - https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2025/Exploits/CVE-2025-59287/proc_creation_win_exploit_cve_2025_59287.yml
author: Huntress Labs, Swachchhanda Shrawan Poudel (Nextron Systems), Huntrule Team
date: 2025-10-31
tags:
  - attack.execution
  - attack.initial-access
  - attack.t1190
  - attack.t1203
  - cve.2025-59287
  - detection.emerging-threats
logsource:
  category: process_creation
  product: windows
detection:
  selection_parent_wsusservice:
    ParentImage|endswith: \wsusservice.exe
  selection_parent_w3wp_wsuspool:
    ParentImage|endswith: \w3wp.exe
    ParentCommandLine|contains: WsusPool
  selection_child:
    Image|endswith:
      - \cmd.exe
      - \powershell.exe
      - \pwsh.exe
      - \powershell_ise.exe
  condition: 1 of selection_parent_* and selection_child
falsepositives:
  - If this activity is expected, consider filtering based on specific command lines, user context (e.g., `nt authority\network service`), or parent process command lines to reduce noise.
level: high
license: DRL-1.1
related:
  - id: 43259cc4-1b80-4931-bd98-baea01afc196
    type: derived

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