name: Powershell Disable Security Monitoring
id: c148a894-dd93-11eb-bf2a-acde48001122
version: 3
date: '2022-07-15'
author: Michael Haag, Splunk
status: production
type: TTP
description: This search is to identifies a modification in registry to disable the
  windows denfender real time behavior monitoring. This event or technique is commonly
  seen in RAT, bot, or Trojan to disable AV to evade detections.
data_source:
- Sysmon Event ID 1
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*"
  AND Processes.process IN ("*disablerealtimemonitoring*","*disableioavprotection*","*disableintrusionpreventionsystem*","*disablescriptscanning*","*disableblockatfirstseen*","*DisableBehaviorMonitoring*","*drtm
  *","*dioavp *","*dscrptsc *","*dbaf *","*dbm *") by Processes.dest Processes.user
  Processes.parent_process Processes.original_file_name Processes.process_name Processes.process
  Processes.process_id Processes.parent_process_id | `drop_dm_object_name(Processes)`
  | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `powershell_disable_security_monitoring_filter`'
how_to_implement: To successfully implement this search you need to be ingesting information
  on process that include the name of the process responsible for the changes from
  your endpoints into the `Endpoint` datamodel in the `Processes` node. In addition,
  confirm the latest CIM App 4.20 or higher is installed and the latest TA for the
  endpoint product.
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
tags:
  analytic_story:
  - Ransomware
  - Revil Ransomware
  asset_type: Endpoint
  confidence: 50
  impact: 50
  message: ''
  mitre_attack_id:
  - T1562.001
  - T1562
  observable:
  - name: ComputerName
    type: Hostname
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - Processes.dest
  - Processes.user
  - Processes.parent_process_name
  - Processes.parent_process
  - Processes.original_file_name
  - Processes.process_name
  - Processes.process
  - Processes.process_id
  - Processes.parent_process_path
  - Processes.process_path
  - Processes.parent_process_id
  risk_score: 25.0
  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