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Detection rules › Sigma

Suspicious Get-ADReplAccount

Status
test
Severity
medium
Log source
product windows, category ps_script
Author
frack113
Source
github.com/SigmaHQ/sigma

The DSInternals PowerShell Module exposes several internal features of Active Directory and Azure Active Directory. These include FIDO2 and NGC key auditing, offline ntds.dit file manipulation, password auditing, DC recovery from IFM backups and password hash calculation.

MITRE ATT&CK coverage

TacticTechniques
Credential AccessT1003.006 OS Credential Dumping: DCSync

Event coverage

ProviderEventTitle
PowerShellEvent ID 4104Creating Scriptblock text (MessageNumber of MessageTotal).

Rule body yaml

title: Suspicious Get-ADReplAccount
id: 060c3ef1-fd0a-4091-bf46-e7d625f60b73
status: test
description: |
    The DSInternals PowerShell Module exposes several internal features of Active Directory and Azure Active Directory.
    These include FIDO2 and NGC key auditing, offline ntds.dit file manipulation, password auditing, DC recovery from IFM backups and password hash calculation.
references:
    - https://www.powershellgallery.com/packages/DSInternals
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1003.006/T1003.006.md#atomic-test-2---run-dsinternals-get-adreplaccount
author: frack113
date: 2022-02-06
tags:
    - attack.credential-access
    - attack.t1003.006
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection:
        ScriptBlockText|contains|all:
            - Get-ADReplAccount
            - '-All '
            - '-Server '
    condition: selection
falsepositives:
    - Legitimate PowerShell scripts
level: medium

Stages and Predicates

Stage 0: condition

selection

Stage 1: selection

selection:
    ScriptBlockText|contains|all:
        - Get-ADReplAccount
        - '-All '
        - '-Server '

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
ScriptBlockTextmatch
  • -All
  • -Server
  • Get-ADReplAccount corpus 2 (sigma 2)