Suspicious Userinit Child Process

 1title: Suspicious Userinit Child Process
 2id: b655a06a-31c0-477a-95c2-3726b83d649d
 3status: test
 4description: Detects a suspicious child process of userinit
 5references:
 6    - https://twitter.com/SBousseaden/status/1139811587760562176
 7author: Florian Roth (Nextron Systems), Samir Bousseaden (idea)
 8date: 2019-06-17
 9modified: 2025-07-04
10tags:
11    - attack.defense-evasion
12    - attack.t1055
13logsource:
14    category: process_creation
15    product: windows
16detection:
17    selection:
18        ParentImage|endswith: '\userinit.exe'
19    filter_main_netlogon:
20        CommandLine|contains: '\netlogon\'
21    filter_main_explorer:
22        - Image|endswith: '\explorer.exe'
23        - OriginalFileName: 'explorer.exe'
24    filter_main_null:
25        Image: null
26    condition: selection and not 1 of filter_main_*
27fields:
28    - CommandLine
29    - ParentCommandLine
30falsepositives:
31    - Administrative scripts
32level: medium