Windows Important Audit Policy Disabled

name: Windows Important Audit Policy Disabled
id: 1bf500e5-1226-41d9-af5d-ed1f577929f2
version: 8
creation_date: '2025-02-19'
modification_date: '2026-05-13'
author: Nasreddine Bencherchali, Splunk
status: production
type: TTP
description: The following analytic detects the disabling of important audit policies. It leverages EventCode 4719 from Windows Security Event Logs to identify changes where success or failure auditing is removed. This activity is significant as it suggests an attacker may have gained access to the domain controller and is attempting to evade detection by tampering with audit policies. If confirmed malicious, this could lead to severe consequences, including data theft, privilege escalation, and full network compromise. Immediate investigation is required to determine the source and intent of the change.
data_source:
    - Windows Event Log Security 4719
search: |-
    `wineventlog_security` EventCode=4719 (AuditPolicyChanges IN ("%%8448","%%8450","%%8448, %%8450") OR Changes IN ("Failure removed","Success removed","Success removed, Failure removed")) `important_audit_policy_subcategory_guids`
      | replace "%%8448" with "Success removed", "%%8450" with "Failure removed", "%%8448, %%8450" with "Success removed, Failure removed" in AuditPolicyChanges
      | eval AuditPolicyChanges=coalesce(AuditPolicyChanges,Changes), SubcategoryGuid=coalesce(SubcategoryGuid,Subcategory_GUID)
      | rename ClientProcessId as process_id
      | stats min(_time) as _time values(host) as dest
        BY AuditPolicyChanges SubcategoryGuid, process_id
      | lookup advanced_audit_policy_guids GUID as SubcategoryGuid OUTPUT Category SubCategory
      | `windows_important_audit_policy_disabled_filter`
how_to_implement: To implement the following query, enable the audit policy sub category "Audit Audit Policy Change", and, ensure you are ingesting EventCode `4719` from your endpoints via the appropriate Splunk Add-on for Microsoft Windows. Update the macro definition with the an accurate list of Audit sub categories that you consider important for your environment.
known_false_positives: No false positives have been identified at this time.
references:
    - https://learn.microsoft.com/en-us/windows/security/threat-protection/auditing/event-4719
drilldown_searches:
    - name: View the detection results for - "$dest$"
      search: '%original_detection_search% | search  dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
finding:
    title: Important audit policy "$SubCategory$" of category "$Category$" was disabled on $dest$
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - Windows Audit Policy Tampering
asset_type: Endpoint
mitre_attack_id:
    - T1685
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test - Security 1
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562.001/disable_gpo/windows-security-xml.log
          source: XmlWinEventLog:Security
          sourcetype: XmlWinEventLog
      description: PORTED MANUAL TEST - This search uses a lookup provided by Enterprise Security and needs to be manually tested
      test_type: experimental
    - name: True Positive Test - Security 2
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562.002/auditpol_tampering/auditpol_tampering_security.log
          source: XmlWinEventLog:Security
          sourcetype: XmlWinEventLog
      description: PORTED MANUAL TEST - This search uses a lookup provided by Enterprise Security and needs to be manually tested
      test_type: experimental