Suspicious Child Process Of Wermgr.EXE — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems). Source status: test; severity: high. Source dates: 2022-10-14 / 2024-08-29.

{
  "category": "process_creation",
  "product": "windows"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: 772a9f60d48c0afe96483be82ca6e833da06f158f751fad42b5973d4410eb4e6

Detection logic

Original source YAML. Source-tag agreement is not proof of complete semantic coverage. This rule has not been compiled for a SIEM backend or validated against live telemetry here.

title: Suspicious Child Process Of Wermgr.EXE
id: 396f6630-f3ac-44e3-bfc8-1b161bc00c4e
related:
    - id: 5394fcc7-aeb2-43b5-9a09-cac9fc5edcd5
      type: similar
status: test
description: Detects suspicious Windows Error Reporting manager (wermgr.exe) child process
references:
    - https://www.trendmicro.com/en_us/research/22/j/black-basta-infiltrates-networks-via-qakbot-brute-ratel-and-coba.html
    - https://www.echotrail.io/insights/search/wermgr.exe
    - https://github.com/binderlabs/DirCreate2System
author: Florian Roth (Nextron Systems)
date: 2022-10-14
modified: 2024-08-29
tags:
    - attack.privilege-escalation
    - attack.stealth
    - attack.t1055
    - attack.t1036
logsource:
    category: process_creation
    product: windows
detection:
    selection:
        ParentImage|endswith: '\wermgr.exe'
        Image|endswith:
            - '\cmd.exe'
            - '\cscript.exe'
            - '\ipconfig.exe'
            - '\mshta.exe'
            - '\net.exe'
            - '\net1.exe'
            - '\netstat.exe'
            - '\nslookup.exe'
            - '\powershell_ise.exe'
            - '\powershell.exe'
            - '\pwsh.exe'
            - '\regsvr32.exe'
            - '\rundll32.exe'
            - '\systeminfo.exe'
            - '\whoami.exe'
            - '\wscript.exe'
    filter_main_rundll32:
        Image|endswith: '\rundll32.exe'
        CommandLine|contains|all:
            - 'C:\Windows\system32\WerConCpl.dll'
            - 'LaunchErcApp '
        CommandLine|contains:
            - '-queuereporting'
            - '-responsepester'
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://www.trendmicro.com/en_us/research/22/j/black-basta-infiltrates-networks-via-qakbot-brute-ratel-and-coba.html
• https://www.echotrail.io/insights/search/wermgr.exe
• https://github.com/binderlabs/DirCreate2System