User Discovery And Export Via Get-ADUser Cmdlet

SIGMA detection rule by Nasreddine Bencherchali (Nextron Systems) · NOASSERTION

Detects usage of the Get-ADUser cmdlet to collect user information and output it to a file

title: User Discovery And Export Via Get-ADUser Cmdlet
id: 1114e048-b69c-4f41-bc20-657245ae6e3f
related:
    - id: c2993223-6da8-4b1a-88ee-668b8bf315e9
      type: similar
status: test
description: Detects usage of the Get-ADUser cmdlet to collect user information and output it to a file
references:
    - http://blog.talosintelligence.com/2022/09/lazarus-three-rats.html
    - https://www.microsoft.com/en-us/security/blog/2022/10/18/defenders-beware-a-case-for-post-ransomware-investigations/
author: Nasreddine Bencherchali (Nextron Systems)
date: 2022-09-09
modified: 2022-11-17
tags:
    - attack.discovery
    - attack.t1033
logsource:
    category: process_creation
    product: windows
detection:
    selection_img:
        - Image|endswith:
              - '\powershell.exe'
              - '\pwsh.exe'
        - OriginalFileName:
              - 'PowerShell.EXE'
              - 'pwsh.dll'
    selection_cli:
        CommandLine|contains|all:
            - 'Get-ADUser '
            - ' -Filter \*'
        CommandLine|contains:
            - ' > '
            - ' | Select '
            - 'Out-File'
            - 'Set-Content'
            - 'Add-Content'
    condition: all of selection_*
falsepositives:
    - Legitimate admin scripts may use the same technique, it's better to exclude specific computers or users who execute these commands or scripts often
level: medium

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

69f7842b-e3e1-4e6b-878b-8c0c66a3d018

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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.

Rejected pattern present

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Format & documentation suggestions

Not a security issue — this rule is valid and was accepted as-is. These are optional fields/conventions its own format recommends, mainly affecting its quality score and how well it documents itself for other reviewers.

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

[[ currentRule.title ]]

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