Suspicious Child Process Of Wermgr.EXE

SIGMA detection rule by Florian Roth (Nextron Systems) · NOASSERTION

Detects suspicious Windows Error Reporting manager (wermgr.exe) child process

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

[[ currentRule.title && currentRule.title.length > 60 ? currentRule.title.slice(0, 60) + '…' : currentRule.title ]]

81471948-d88a-4f0d-a429-ebf03f330869

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Executable code, not a declarative rule

This submission is arbitrary [[ currentRule.format ? currentRule.format.toUpperCase() : '' ]] code, not a declarative detection rule — review it as you would any script before running it, and note that it cannot be safely aggregated or auto-executed alongside YARA/Sigma/Suricata/CRS rules.

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