User Added to Local Administrator Group

SIGMA detection rule by Florian Roth (Nextron Systems) · GPL-2.0

Detects the addition of a new member to the local administrator group, which could be legitimate activity or a sign of privilege escalation activity

title: User Added to Local Administrator Group
id: 6695d6a2-9365-ee87-ccdd-966b0e1cdbd4
related:
    - id: c265cf08-3f99-46c1-8d59-328247057d57
      type: derived
status: stable
description: Detects the addition of a new member to the local administrator group, which could be legitimate activity or a sign of privilege escalation activity
references:
    - https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-10/security/threat-protection/auditing/event-4732
    - https://learn.microsoft.com/en-us/windows-server/identity/ad-ds/manage/understand-security-identifiers
author: Florian Roth (Nextron Systems)
date: 2017-03-14
modified: 2021-01-17
tags:
    - attack.initial-access
    - attack.privilege-escalation
    - attack.stealth
    - attack.t1078
    - attack.persistence
    - attack.t1098
logsource:
    product: windows
    service: security
detection:
    security:
        Channel: Security
    selection_eid:
        EventID: 4732
    selection_group:
        - TargetUserName|startswith: Administr
        - TargetSid: S-1-5-32-544
    filter_main_computer_accounts:
        SubjectUserName|endswith: $
    condition: security and (all of selection_* and not 1 of filter_*)
falsepositives:
    - Legitimate administrative activity
level: medium
ruletype: Sigma

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

52d852cd-1e91-49e4-82c6-410f7ad0fcd6

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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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