Detection rules › Splunk

Windows Audit Policy Disabled via Auditpol

Status
production
Severity
low
Group by
IntegrityLevel, command_line, computer_name, event_action, original_file_name, parent_command_line, parent_process_guid, parent_process_id, parent_process_name, process_guid, process_hash, process_id, process_name, user, user_id, vendor_product
Author
Nasreddine Bencherchali, Splunk
Source
github.com/splunk/security_content

The following analytic identifies the execution of auditpol.exe with the "/set" command-line argument in order to disable a specific category or sub-category from the audit policy. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity can be significant as it indicates potential defense evasion by adversaries or Red Teams, aiming to limit data that can be leveraged for detections and audits. If confirmed malicious, this behavior could allow attackers to bypass defenses, and plan further attacks, potentially leading to full machine compromise or lateral movement.

Known false positives

  • False positives should be rare, investigate the activity, and apply additional filters when necessary.

MITRE ATT&CK coverage

Telemetry coverage

Rule body

name: Windows Audit Policy Disabled via Auditpol
id: 14e008e5-6723-4298-b0d4-e95b24e10c18
version: 8
creation_date: '2025-02-19'
modification_date: '2026-05-13'
author: Nasreddine Bencherchali, Splunk
status: production
type: Anomaly
description: The following analytic identifies the execution of `auditpol.exe` with the "/set" command-line argument in order to disable a specific category or sub-category from the audit policy. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names and command-line executions. This activity can be significant as it indicates potential defense evasion by adversaries or Red Teams, aiming to limit data that can be leveraged for detections and audits. 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 1
    - Windows Event Log Security 4688
    - CrowdStrike ProcessRollup2
search: |-
    | tstats `security_content_summariesonly` values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
      WHERE `process_auditpol` Processes.process="*/set*" Processes.process IN ("*/success:*", "*/failure:*") Processes.process="*disable*"
        AND
        NOT Processes.process IN ("*/?*", "*/exclude*")
      BY Processes.action Processes.dest Processes.original_file_name
         Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
         Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
         Processes.process Processes.process_exec Processes.process_guid
         Processes.process_hash Processes.process_id Processes.process_integrity_level
         Processes.process_name Processes.process_path Processes.user
         Processes.user_id Processes.vendor_product
    | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_audit_policy_disabled_via_auditpol_filter`
how_to_implement: The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process name, and process original file name. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives: False positives should be rare, investigate the activity, and apply additional filters when necessary.
references:
    - https://www.microsoft.com/en-us/security/blog/2021/01/20/deep-dive-into-the-solorigate-second-stage-activation-from-sunburst-to-teardrop-and-raindrop/
    - https://www.cybereason.com/blog/research/prometei-botnet-exploiting-microsoft-exchange-vulnerabilities
    - https://attack.mitre.org/techniques/T1562/002/
    - https://learn.microsoft.com/en-us/windows-server/administration/windows-commands/auditpol-set
intermediate_findings:
    entities:
        - field: user
          type: user
          score: 20
          message: An instance of $parent_process_name$ spawning $process_name$ with CommandLine $process$ was identified attempting to disable and audit policy category/sub-category on $dest$ by user $user$.
        - field: dest
          type: system
          score: 20
          message: An instance of $parent_process_name$ spawning $process_name$ with CommandLine $process$ was identified attempting to disable and audit policy category/sub-category on $dest$ by user $user$.
threat_objects:
    - field: process_name
      type: process_name
analytic_story:
    - Windows Audit Policy Tampering
asset_type: Endpoint
mitre_attack_id:
    - T1685.001
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint

Stages and Predicates

Stage 1: tstats

| tstats `security_content_summariesonly` values(Processes.process) as process min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Processes
  WHERE `process_auditpol` Processes.process="*/set*" Processes.process IN ("*/success:*", "*/failure:*") Processes.process="*disable*"
    AND
    NOT Processes.process IN ("*/?*", "*/exclude*")
  BY Processes.action Processes.dest Processes.original_file_name
     Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid
     Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path
     Processes.process Processes.process_exec Processes.process_guid
     Processes.process_hash Processes.process_id Processes.process_integrity_level
     Processes.process_name Processes.process_path Processes.user
     Processes.user_id Processes.vendor_product

Stage 2: search

| `drop_dm_object_name(Processes)`

Stage 3: search

| `security_content_ctime(firstTime)`

Stage 4: search

| `security_content_ctime(lastTime)`

Stage 5: search

| `windows_audit_policy_disabled_via_auditpol_filter`

Exclusions

The rule actively suppresses these predicates.

FieldKindExcluded valuesSearch
Processes.processin"*/?*", "*/exclude*"excludes:Processes.process

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Processes.original_file_nameeq
  • "AUDITPOL.EXE" corpus 10 (splunk 8, sigma 1, elastic 1)
field:"OriginalFileName" kind:eq
Processes.processeq
  • "*/set*" corpus 6 (splunk 5, kusto 1)
  • "*disable*" corpus 13 (sigma 10, splunk 3)
field:"CommandLine" kind:eq
Processes.processin
  • "*/failure:*"
  • "*/success:*"
field:"CommandLine" kind:in
Processes.process_nameeq
  • "auditpol.exe" corpus 10 (splunk 8, elastic 2)
field:"process_name" kind:eq