Windows Defender ASR Audit Events

name: Windows Defender ASR Audit Events
id: 0e4d46b1-22bd-4f0e-8337-ca6f60ad4bea
version: 8
date: '2026-04-15'
author: Michael Haag, Splunk
status: production
type: Anomaly
data_source:
    - Windows Event Log Defender 1122
    - Windows Event Log Defender 1125
    - Windows Event Log Defender 1126
    - Windows Event Log Defender 1132
    - Windows Event Log Defender 1134
description: This detection searches for Windows Defender ASR audit events. ASR is a feature of Windows Defender Exploit Guard that prevents actions and apps that are typically used by exploit-seeking malware to infect machines. ASR rules are applied to processes and applications. When a process or application attempts to perform an action that is blocked by an ASR rule, an event is generated. This detection searches for ASR audit events that are generated when a process or application attempts to perform an action that would be blocked by an ASR rule, but is allowed to proceed for auditing purposes.
search: |-
    `ms_defender` EventCode IN (1122, 1125, 1126, 1132, 1134)
      | stats count min(_time) as firstTime max(_time) as lastTime
        BY host, Process_Name, Target_Commandline,
           Path, ID, EventCode
      | lookup asr_rules ID OUTPUT ASR_Rule
      | fillnull value=NULL
      | `security_content_ctime(firstTime)`
      | `security_content_ctime(lastTime)`
      | rename host as dest
      | `windows_defender_asr_audit_events_filter`
how_to_implement: The following analytic requires collection of Windows Defender Operational logs in either XML or multi-line. To collect, setup a new input for the Windows Defender Operational logs. In addition, it does require a lookup that maps the ID to ASR Rule name. Note that Audit and block Event IDs have different fields, therefore the analytic will need to be modified for each type of event.
known_false_positives: False positives are expected from legitimate applications generating events that are similar to those generated by malicious activity. For example, Event ID 1122 is generated when a process attempts to load a DLL that is blocked by an ASR rule. This can be triggered by legitimate applications that attempt to load DLLs that are not blocked by ASR rules. This is audit only.
references:
    - https://asrgen.streamlit.app/
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"
rba:
    message: ASR audit event, $ASR_Rule$, was triggered on $dest$.
    risk_objects:
        - field: dest
          type: system
          score: 20
    threat_objects: []
tags:
    analytic_story:
        - Windows Attack Surface Reduction
    asset_type: Endpoint
    atomic_guid: []
    mitre_attack_id:
        - T1059
        - T1566.001
        - T1566.002
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1059/defender/asr_audit.log
          source: WinEventLog:Microsoft-Windows-Windows Defender/Operational
          sourcetype: XmlWinEventLog