Suspicious Computer Account Name Change CVE-2021-42287

Detects the renaming of an existing computer account to a account name that doesn't contain a $ symbol as seen in attacks against CVE-2021-42287

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Detection logic

selection

EventID: 4781
OldTargetUserName|contains: $

filter

NewTargetUserName|contains: $

Condition

selection and not filter

Raw YAML

title: Suspicious Computer Account Name Change CVE-2021-42287
id: 45eb2ae2-9aa2-4c3a-99a5-6e5077655466
status: test
description: Detects the renaming of an existing computer account to a account name that doesn't contain a $ symbol as seen in attacks against CVE-2021-42287
references:
    - https://medium.com/@mvelazco/hunting-for-samaccountname-spoofing-cve-2021-42287-and-domain-controller-impersonation-f704513c8a45
author: Florian Roth (Nextron Systems)
date: 2021-12-22
modified: 2022-12-25
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.stealth
    - attack.t1036
    - attack.t1098
    - cve.2021-42287
    - detection.emerging-threats
logsource:
    product: windows
    service: security
detection:
    selection:
        EventID: 4781 # rename user
        OldTargetUserName|contains: '$'
    filter:
        NewTargetUserName|contains: '$'
    condition: selection and not filter
falsepositives:
    - Unknown
level: high