name: Windows DISM Remove Defender
id: 8567da9e-47f0-11ec-99a9-acde48001122
version: 1
date: '2021-11-17'
author: Michael Haag, Splunk
status: production
type: TTP
description: The following analytic identifies the use of the Windows Disk Image Utility,
  `dism.exe`, to remove Windows Defender. Adversaries may use `dism.exe` to disable
  Defender before completing their objective.
data_source:
- Sysmon Event ID 1
search:
  selection1:
    Image|endswith: dism.exe
  selection2:
    CommandLine: '*/disable-feature*'
  selection3:
    CommandLine: '*/online*'
  selection4:
    CommandLine: '*Windows-Defender*'
  selection5:
    CommandLine: '*/remove*'
  condition: selection1 and selection2 and selection3 and selection4 and selection5
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: Some legitimate administrative tools leverage `dism.exe` to
  manipulate packages and features of the operating system. Filter as needed.
references:
- https://thedfirreport.com/2020/11/23/pysa-mespinoza-ransomware/
tags:
  analytic_story:
  - Windows Defense Evasion Tactics
  asset_type: Endpoint
  confidence: 100
  impact: 80
  message: An instance of $parent_process_name$ spawning $process_name$ was identified
    on endpoint $dest$ by user $user$ attempting to disable Windows Defender.
  mitre_attack_id:
  - T1562.001
  - T1562
  observable:
  - name: user
    type: User
    role:
    - Victim
  - name: dest
    type: Hostname
    role:
    - Victim
  - name: parent_process_name
    type: Process
    role:
    - Parent Process
  - name: process_name
    type: Process
    role:
    - Child Process
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  risk_score: 80
  security_domain: access
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562.001/atomic_red_team/windows-sysmon_dism.log
    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
    sourcetype: xmlwineventlog