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Windows DHCP Server Suspicious Child Process - STRICT

SIGMA detection rule by Adama ASSIONGBON (SOC & CTI Consultant), https://linkedin.com/in/adama-assiongbon-9029893a · Unknown

Detects the Windows DHCP Server service host spawning a shell, script host, or download utility, indicating high-confidence post-exploitation behavior potentially associated with CVE-2026-50518. SOC L1 should verify the source, affected host, user, process or request fields, timing, and related activity. Détecte le processus hôte du service DHCP Server lançant un shell, un moteur de script ou un utilitaire de téléchargement, signe post-exploitation haute confiance potentiellement associé à CVE-2026-50518. Le SOC L1 doit vérifier la source, l’hôte affecté, l’utilisateur, les champs de processus ou de requête, la chronologie et les activités associées.

title: Windows DHCP Server Suspicious Child Process - STRICT
id: 9e1c4202-14ee-4b7c-a7db-95f75297e217
status: experimental
description: |
  Detects the Windows DHCP Server service host spawning a shell, script host, or download utility, indicating high-confidence post-exploitation behavior potentially associated with CVE-2026-50518. SOC L1 should verify the source, affected host, user, process or request fields, timing, and related activity.
  Détecte le processus hôte du service DHCP Server lançant un shell, un moteur de script ou un utilitaire de téléchargement, signe post-exploitation haute confiance potentiellement associé à CVE-2026-50518. Le SOC L1 doit vérifier la source, l’hôte affecté, l’utilisateur, les champs de processus ou de requête, la chronologie et les activités associées.
references:
  - https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-50518
author: Adama ASSIONGBON (SOC & CTI Consultant), https://linkedin.com/in/adama-assiongbon-9029893a
date: 2026-07-16
logsource:
  product: windows
  category: process_creation
detection:
  selection_parent:
    ParentImage|endswith: '\svchost.exe'
    ParentCommandLine|contains: 'DHCPServer'
  selection_child:
    Image|endswith:
      - '\cmd.exe'
      - '\powershell.exe'
      - '\pwsh.exe'
      - '\wscript.exe'
      - '\cscript.exe'
      - '\mshta.exe'
      - '\rundll32.exe'
      - '\certutil.exe'
      - '\bitsadmin.exe'
      - '\curl.exe'
  condition: all of selection_*
fields:
  - UtcTime
  - EventID
  - Computer
  - User
  - Image
  - CommandLine
  - ParentImage
  - ParentCommandLine
  - IntegrityLevel
  - ProcessId
  - ParentProcessId
falsepositives:
  - Authorized debugging of the DHCP Server service on an isolated host
level: critical
tags:
  - attack.execution
  - attack.t1059
  - cve.2026-50518

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Executable code, not a declarative rule

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