Suspicious Windows Update Agent Empty Cmdline — Sigma Rule

Rule metadata and linked tags

Author: Florian Roth (Nextron Systems). Source status: test; severity: high. Source dates: 2022-02-26 / 2023-11-11.

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

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: c0b388ad4c104d12647e53c9801e5de6bfeb144b3863342b063db09a4659e9dd

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 Windows Update Agent Empty Cmdline
id: 52d097e2-063e-4c9c-8fbb-855c8948d135
status: test
description: |
    Detects suspicious Windows Update Agent activity in which a wuauclt.exe process command line doesn't contain any command line flags
references:
    - https://redcanary.com/blog/blackbyte-ransomware/
author: Florian Roth (Nextron Systems)
date: 2022-02-26
modified: 2023-11-11
tags:
    - attack.stealth
    - attack.t1036
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith: '\Wuauclt.exe'
        - OriginalFileName: 'Wuauclt.exe'
    selection_cli:
        CommandLine|endswith:
            - 'Wuauclt'
            - 'Wuauclt.exe'
    condition: all of selection*
falsepositives:
    - Unknown
level: high

Original YAML and metadata in JSON

False positives

• Unknown

Source references

• https://redcanary.com/blog/blackbyte-ransomware/