Detection rules › Sigma
Exploitation Activity of CVE-2025-59287 - WSUS Suspicious Child Process
Detects the creation of command-line interpreters (cmd.exe, powershell.exe) as child processes of Windows Server Update Services (WSUS) related process wsusservice.exe. This behavior is a key indicator of exploitation for the critical remote code execution vulnerability such as CVE-2025-59287, where attackers spawn shells to conduct reconnaissance and further post-exploitation activities.
Known false positives
- 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.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access | |
| Execution |
Telemetry coverage
| Provider | Record / event type |
|---|---|
| Sysmon | Event ID 1: Process creation |
Rule body
title: Exploitation Activity of CVE-2025-59287 - WSUS Suspicious Child Process
id: 43259cc4-1b80-4931-bd98-baea01afc196
status: experimental
description: |
Detects the creation of command-line interpreters (cmd.exe, powershell.exe) as child processes of Windows Server Update Services (WSUS) related process wsusservice.exe.
This behavior is a key indicator of exploitation for the critical remote code execution vulnerability such as CVE-2025-59287, where attackers spawn shells to conduct reconnaissance and further post-exploitation activities.
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
author: Huntress Labs, Swachchhanda Shrawan Poudel (Nextron Systems)
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
Stages and Predicates
Stage 0: condition
1 of selection_parent_* and selection_childStage 1: selection_parent_wsusservice
selection_parent_wsusservice:
ParentImage|endswith: '\wsusservice.exe'
Stage 2: selection_parent_w3wp_wsuspool
selection_parent_w3wp_wsuspool:
ParentImage|endswith: '\w3wp.exe'
ParentCommandLine|contains: 'WsusPool'
Stage 3: selection_child
selection_child:
Image|endswith:
- '\cmd.exe'
- '\powershell.exe'
- '\pwsh.exe'
- '\powershell_ise.exe'
Indicators
These rows show field, operator, and value matches.
| Field | Kind | Values | Search |
|---|---|---|---|
Image | ends_with |
| field:"Image" kind:ends_with |
ParentCommandLine | match |
| field:"ParentCommandLine" kind:match value:"WsusPool" |
ParentImage | ends_with |
| field:"ParentImage" kind:ends_with |