splunk-security_content/detections/endpoint/powershell_remove_windows_defender_directory.yml

name: Powershell Remove Windows Defender Directory
id: adf47620-79fa-11ec-b248-acde48001122
version: 4
date: '2024-05-18'
author: Teoderick Contreras, Splunk
status: production
type: TTP
description: The following analytic detects a suspicious PowerShell command attempting
  to delete the Windows Defender directory. It leverages PowerShell Script Block Logging
  to identify commands containing "rmdir" and targeting the Windows Defender path.
  This activity is significant as it may indicate an attempt to disable or corrupt
  Windows Defender, a key security component. If confirmed malicious, this action
  could allow an attacker to bypass endpoint protection, facilitating further malicious
  activities without detection.
data_source:
- Powershell Script Block Logging 4104
search: '`powershell` EventCode=4104 ScriptBlockText = "*rmdir *" AND ScriptBlockText
  = "*\\Microsoft\\Windows Defender*" | stats count min(_time) as firstTime max(_time)
  as lastTime by Opcode Computer UserID EventCode ScriptBlockText | `security_content_ctime(firstTime)`
  | `security_content_ctime(lastTime)` | `powershell_remove_windows_defender_directory_filter`'
how_to_implement: To successfully implement this analytic, you will need to enable
  PowerShell Script Block Logging on some or all endpoints. Additional setup here
  https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.
known_false_positives: unknown
references:
- https://www.microsoft.com/security/blog/2022/01/15/destructive-malware-targeting-ukrainian-organizations/
tags:
  analytic_story:
  - Data Destruction
  - WhisperGate
  asset_type: Endpoint
  confidence: 90
  impact: 100
  message: suspicious powershell script $ScriptBlockText$ was executed on the $Computer$
  mitre_attack_id:
  - T1562.001
  - T1562
  observable:
  - name: Computer
    type: Hostname
    role:
    - Victim
  - name: UserID
    type: User
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  required_fields:
  - _time
  - ScriptBlockText
  - Opcode
  - Computer
  - UserID
  - EventCode
  risk_score: 90
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: 
      https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1059.001/powershell_script_block_logging/sbl_xml.log
    source: XmlWinEventLog:Microsoft-Windows-PowerShell/Operational
    sourcetype: xmlwineventlog