DSInternals Suspicious PowerShell Cmdlets - ScriptBlock — Sigma Rule

Rule metadata and linked tags

Author: Nasreddine Bencherchali (Nextron Systems). Source status: test; severity: high. Source dates: 2024-06-26 / not supplied.

{
  "product": "windows",
  "category": "ps_script",
  "definition": "Requirements: Script Block Logging must be enabled"
}

Pinned original Sigma rule · Detection Rule License 1.1

Source SHA-256: b29d67eb87276e1c6ed08db0f5aea11044d1eab064fdfcddfdaf87b21b42709a

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: DSInternals Suspicious PowerShell Cmdlets - ScriptBlock
id: 846c7a87-8e14-4569-9d49-ecfd4276a01c
related:
    - id: 43d91656-a9b2-4541-b7e2-6a9bd3a13f4e
      type: similar
status: test
description: |
    Detects execution and usage of the DSInternals PowerShell module. Which can be used to perform what might be considered as suspicious activity such as dumping DPAPI backup keys or manipulating NTDS.DIT files.
    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://github.com/MichaelGrafnetter/DSInternals/blob/39ee8a69bbdc1cfd12c9afdd7513b4788c4895d4/Src/DSInternals.PowerShell/DSInternals.psd1
author: Nasreddine Bencherchali (Nextron Systems)
date: 2024-06-26
tags:
    - attack.execution
    - attack.t1059.001
logsource:
    product: windows
    category: ps_script
    definition: 'Requirements: Script Block Logging must be enabled'
detection:
    selection:
        ScriptBlockText|contains:
            - 'Add-ADDBSidHistory'
            - 'Add-ADNgcKey'
            - 'Add-ADReplNgcKey'
            - 'ConvertFrom-ADManagedPasswordBlob'
            - 'ConvertFrom-GPPrefPassword'
            - 'ConvertFrom-ManagedPasswordBlob'
            - 'ConvertFrom-UnattendXmlPassword'
            - 'ConvertFrom-UnicodePassword'
            - 'ConvertTo-AADHash'
            - 'ConvertTo-GPPrefPassword'
            - 'ConvertTo-KerberosKey'
            - 'ConvertTo-LMHash'
            - 'ConvertTo-MsoPasswordHash'
            - 'ConvertTo-NTHash'
            - 'ConvertTo-OrgIdHash'
            - 'ConvertTo-UnicodePassword'
            - 'Disable-ADDBAccount'
            - 'Enable-ADDBAccount'
            - 'Get-ADDBAccount'
            - 'Get-ADDBBackupKey'
            - 'Get-ADDBDomainController'
            - 'Get-ADDBGroupManagedServiceAccount'
            - 'Get-ADDBKdsRootKey'
            - 'Get-ADDBSchemaAttribute'
            - 'Get-ADDBServiceAccount'
            - 'Get-ADDefaultPasswordPolicy'
            - 'Get-ADKeyCredential' # Covers 'Get-ADKeyCredentialLink'
            - 'Get-ADPasswordPolicy'
            - 'Get-ADReplAccount'
            - 'Get-ADReplBackupKey'
            - 'Get-ADReplicationAccount'
            - 'Get-ADSIAccount'
            - 'Get-AzureADUserEx'
            - 'Get-BootKey'
            - 'Get-KeyCredential'
            - 'Get-LsaBackupKey'
            - 'Get-LsaPolicy' # Covers 'Get-LsaPolicyInformation'
            - 'Get-SamPasswordPolicy'
            - 'Get-SysKey'
            - 'Get-SystemKey'
            - 'New-ADDBRestoreFromMediaScript'
            - 'New-ADKeyCredential' # Covers 'New-ADKeyCredentialLink'
            - 'New-ADNgcKey'
            - 'New-NTHashSet'
            - 'Remove-ADDBObject'
            - 'Save-DPAPIBlob'
            - 'Set-ADAccountPasswordHash'
            - 'Set-ADDBAccountPassword' # Covers 'Set-ADDBAccountPasswordHash'
            - 'Set-ADDBBootKey'
            - 'Set-ADDBDomainController'
            - 'Set-ADDBPrimaryGroup'
            - 'Set-ADDBSysKey'
            - 'Set-AzureADUserEx'
            - 'Set-LsaPolicy' # Covers 'Set-LSAPolicyInformation'
            - 'Set-SamAccountPasswordHash'
            - 'Set-WinUserPasswordHash'
            - 'Test-ADDBPasswordQuality'
            - 'Test-ADPasswordQuality'
            - 'Test-ADReplPasswordQuality'
            - 'Test-PasswordQuality'
            - 'Unlock-ADDBAccount'
            - 'Write-ADNgcKey'
            - 'Write-ADReplNgcKey'
    condition: selection
falsepositives:
    - Legitimate usage of DSInternals for administration or audit purpose.
level: high

Original YAML and metadata in JSON

False positives

• Legitimate usage of DSInternals for administration or audit purpose.

Source references

• https://github.com/MichaelGrafnetter/DSInternals/blob/39ee8a69bbdc1cfd12c9afdd7513b4788c4895d4/Src/DSInternals.PowerShell/DSInternals.psd1