Kerberos Pre-Authentication Flag Disabled with PowerShell

name: Kerberos Pre-Authentication Flag Disabled with PowerShell
id: 59b51620-94c9-11ec-b3d5-acde48001122
version: 13
creation_date: '2022-02-23'
modification_date: '2026-05-13'
author: Mauricio Velazco, Splunk
status: production
type: TTP
description: The following analytic detects the use of the `Set-ADAccountControl` PowerShell cmdlet with parameters that disable Kerberos Pre-Authentication. It leverages PowerShell Script Block Logging (EventCode=4104) to identify this specific command execution. Disabling Kerberos Pre-Authentication is significant because it allows adversaries to perform offline brute force attacks against user passwords using the AS-REP Roasting technique. If confirmed malicious, this activity could enable attackers to escalate privileges or maintain persistence within an Active Directory environment, posing a severe security risk.
data_source:
    - Powershell Script Block Logging 4104
search: |-
    `powershell` EventCode=4104 (ScriptBlockText = "*Set-ADAccountControl*" AND ScriptBlockText="*DoesNotRequirePreAuth:$true*")
      | fillnull
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY dest signature signature_id
           user_id vendor_product EventID
           Guid Opcode Name
           Path ProcessID ScriptBlockId
           ScriptBlockText
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | `kerberos_pre_authentication_flag_disabled_with_powershell_filter`
how_to_implement: To successfully implement this analytic, you will need to enable PowerShell Script Block Logging on some or all endpoints. Additional setup here https://help.splunk.com/en/security-offerings/splunk-user-behavior-analytics/get-data-in/5.4.1/add-other-data-to-splunk-uba/configure-powershell-logging-to-see-powershell-anomalies-in-splunk-uba.
known_false_positives: Although unlikely, Administrators may need to set this flag for legitimate purposes.
references:
    - https://docs.microsoft.com/en-us/troubleshoot/windows-server/identity/useraccountcontrol-manipulate-account-properties
    - https://m0chan.github.io/2019/07/31/How-To-Attack-Kerberos-101.html
    - https://stealthbits.com/blog/cracking-active-directory-passwords-with-as-rep-roasting/
finding:
    title: Kerberos Pre Authentication was Disabled using PowerShell on $dest$
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - Active Directory Kerberos Attacks
asset_type: Endpoint
mitre_attack_id:
    - T1558.004
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint