Windows Audit Policy Auditing Option Modified - Registry

name: Windows Audit Policy Auditing Option Modified - Registry
id: 27914692-9c62-44ea-9129-ceb429b61bd0
version: 7
creation_date: '2025-02-19'
modification_date: '2026-05-13'
author: Nasreddine Bencherchali, Bhavin Patel, Splunk
status: production
type: Anomaly
description: The following analytic detects potentially suspicious modifications to the Audit Policy auditing options registry values. It leverages data from the Endpoint.Registry data model, focusing on changes to one of the following auditing option values "CrashOnAuditFail", "FullPrivilegeAuditing", "AuditBaseObjects" and "AuditBaseDirectories" within the "HKLM\\System\\CurrentControlSet\\Control\\Lsa\\" registry key. This activity is significant as it could be a sign of a threat actor trying to tamper with the audit policy configuration, and disabling SACLs configuration. If confirmed malicious, this behavior could allow attackers to bypass defenses, and plan further attacks, potentially leading to full machine compromise or lateral movement.
data_source:
    - Sysmon EventID 13
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry WHERE Registry.registry_path="*\\Control\\Lsa*" Registry.registry_value_name IN ("CrashOnAuditFail", "FullPrivilegeAuditing", "AuditBaseObjects", "AuditBaseDirectories") by Registry.action Registry.dest Registry.process_guid Registry.process_id Registry.registry_hive Registry.registry_path Registry.registry_key_name Registry.registry_value_data Registry.registry_value_name Registry.registry_value_type Registry.status Registry.user Registry.vendor_product | `drop_dm_object_name(Registry)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_audit_policy_auditing_option_modified___registry_filter`'
how_to_implement: To successfully implement this search, you need to be ingesting logs with the registry value name, registry path, and registry value data from your endpoints. If you are using Sysmon, you must have at least version 2.0 of the official Sysmon TA. https://splunkbase.splunk.com/app/5709
known_false_positives: Active setup installer may add or modify this registry.
references:
    - https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-gpac/262a2bed-93d4-4c04-abec-cf06e9ec72fd
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/auditpol-set
drilldown_searches:
    - name: View the detection results for - "$dest$" and "$user$"
      search: '%original_detection_search% | search  dest = "$dest$" user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$" and "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$", "$user$") | 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"
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: The auditing option $registry_value_name$ from the configured Audit Policy was modified on $dest$.
        - field: user
          type: user
          score: 20
          message: The auditing option $registry_value_name$ from the configured Audit Policy was modified on $dest$.
analytic_story:
    - Windows Audit Policy Tampering
asset_type: Endpoint
mitre_attack_id:
    - T1547.014
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test - Sysmon
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562.002/auditpol_tampering/auditpol_tampering_sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit