SigmaHQ/rules/windows/process_creation/win_proc_wrong_parent.yml

title: Windows Processes Suspicious Parent Directory
id: 96036718-71cc-4027-a538-d1587e0006a7
status: experimental
description: Detect suspicious parent processes of well-known Windows processes
author: vburov
references:
    - https://securitybytes.io/blue-team-fundamentals-part-two-windows-processes-759fe15965e2
    - https://www.carbonblack.com/2014/06/10/screenshot-demo-hunt-evil-faster-than-ever-with-carbon-black/
    - https://www.13cubed.com/downloads/windows_process_genealogy_v2.pdf
    - https://attack.mitre.org/techniques/T1036/
date: 2019/02/23
modified: 2020/11/28
tags:
    - attack.defense_evasion
    - attack.t1036 # an old one
    - attack.t1036.003
    - attack.t1036.005
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        Image|endswith:
            - '\svchost.exe'
            - '\taskhost.exe'
            - '\lsm.exe'
            - '\lsass.exe'
            - '\services.exe'
            - '\lsaiso.exe'
            - '\csrss.exe'
            - '\wininit.exe'
            - '\winlogon.exe'
    filter1:
        - ParentImage|endswith: '\SavService.exe'
        - ParentImage|contains:
            - '\System32\'
            - '\SysWOW64\'
    filter2:
        ParentImage|contains:
            - '\Windows Defender\'
            - '\Microsoft Security Client\'
        ParentImage|endswith: '\MsMpEng.exe'
    filter_null:
        ParentImage: null
    condition: selection and not filter1 and not filter2 and not filter_null
falsepositives:
    - Some security products seem to spawn these
level: low