Powershell Disable Security Monitoring

name: Powershell Disable Security Monitoring
id: c148a894-dd93-11eb-bf2a-acde48001122
version: 16
creation_date: '2021-07-05'
modification_date: '2026-05-13'
author: Michael Haag, Nasreddine Bencherchali, Splunk
status: production
type: TTP
description: |
    The following analytic identifies attempts to disable Windows Defender
    real-time behavior monitoring via PowerShell commands. It detects the use of specific
    `Set-MpPreference` parameters that disable various security features. This activity
    is significant as it is commonly used by malware such as RATs, bots, or Trojans
    to evade detection by disabling antivirus protections. If confirmed malicious, this
    action could allow an attacker to operate undetected, leading to potential data
    exfiltration, further system compromise, or persistent access within the environment.
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
    `process_powershell`
    Processes.process="*Set-MpPreference*"
    (
      Processes.process IN (
        "*DisableArchiveScanning*",
        "*DisableBehaviorMonitoring*",
        "*DisableBlockAtFirstSeen*",
        "*DisableCatchupFullScan*",
        "*DisableCatchupQuickScan*",
        "*DisableIOAVProtection*",
        "*DisableRealtimeMonitoring*",
        "*DisableRemovableDriveScanning*",
        "*DisableRestorePoint*",
        "*DisableScanningMappedNetworkDrivesForFullScan*",
        "*DisableScanningNetworkFiles*",
        "*DisableScriptScanning*",
        "*drdsc*",
        "*dsnf *",
        "*drtm *",
        "*dioavp *",
        "*dscrptsc *",
        "*dbaf *",
        "*darchsc *",
        "*dcfsc *",
        "*dbm *"
      )
      Processes.process IN (
        "* $true*",
        "* 1*"
      )
    )
    OR
    (
      Processes.process = "*PUAProtection*"
      Processes.process = "*disable*"
    )
    OR
    (
      Processes.process = "*CloudBlockLevel*"
      Processes.process IN (
        "* $false*",
        "* 0*"
      )
    )
    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)`
    | `powershell_disable_security_monitoring_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: |
    Limited false positives. However, tune based on scripts that may perform this action.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1562.001/T1562.001.md#atomic-test-15---tamper-with-windows-defender-atp-powershell
    - https://docs.microsoft.com/en-us/powershell/module/defender/set-mppreference?view=windowsserver2022-ps
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: Windows Defender Real-time Behavior Monitoring disabled on $dest$
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - Ransomware
    - Revil Ransomware
    - CISA AA24-241A
    - BlankGrabber Stealer
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
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562.001/pwh_defender_disabling/windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit