Add or Set Windows Defender Exclusion

name: Add or Set Windows Defender Exclusion
id: 773b66fe-4dd9-11ec-8289-acde48001122
version: 14
date: '2026-03-10'
author: Teoderick Contreras, Nasreddine Bencherchali, Splunk
status: production
type: TTP
description: |
    The following analytic detects the use of commands to add or set exclusions
    in Windows Defender. It leverages data from Endpoint Detection and Response (EDR)
    agents, focusing on command-line executions involving "Add-MpPreference" or "Set-MpPreference"
    with exclusion parameters. This activity is significant because adversaries often
    use it to bypass Windows Defender, allowing malicious code to execute undetected.
    If confirmed malicious, this behavior could enable attackers to evade antivirus
    detection, maintain persistence, and execute further malicious activities without
    interference from Windows Defender.
data_source:
    - Sysmon EventID 1
    - Windows Event Log Security 4688
    - CrowdStrike ProcessRollup2
search: |
    | tstats `security_content_summariesonly` count min(_time) as firstTime max(_time)
    as lastTime from datamodel=Endpoint.Processes where
    (
      Processes.process = "*Add-MpPreference *"
      OR
      Processes.process = "*Set-MpPreference *"
    )
    Processes.process IN (
          "*-Exclusion*",
          "*-ControlledFolderAccessAllowedApplications*",
          "*-AttackSurfaceReductionOnlyExclusions*"
          )
    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)`
    | `add_or_set_windows_defender_exclusion_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 GUID, process name, and parent process.
    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: |
    Admin or user may choose to use this windows features. Filter as needed.
references:
    - https://tccontre.blogspot.com/2020/01/remcos-rat-evading-windows-defender-av.html
    - https://app.any.run/tasks/cf1245de-06a7-4366-8209-8e3006f2bfe5/
    - https://www.microsoft.com/security/blog/2022/01/15/destructive-malware-targeting-ukrainian-organizations/
    - https://learn.microsoft.com/en-us/powershell/module/defender/add-mppreference?view=windowsserver2025-ps
drilldown_searches:
    - name: View the detection results for - "$user$" and "$dest$"
      search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$" and "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") starthoursago=168  | 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: $info_min_time$
      latest_offset: $info_max_time$
rba:
    message: exclusion command $process$ executed on $dest$
    risk_objects:
        - field: user
          type: user
          score: 50
        - field: dest
          type: system
          score: 50
    threat_objects: []
tags:
    analytic_story:
        - Compromised Windows Host
        - AgentTesla
        - Data Destruction
        - Remcos
        - CISA AA22-320A
        - ValleyRAT
        - XWorm
        - WhisperGate
        - Windows Defense Evasion Tactics
        - Crypto Stealer
        - NetSupport RMM Tool Abuse
    asset_type: Endpoint
    mitre_attack_id:
        - T1562.001
    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/T1562.001/defender_exclusion_sysmon/sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog