powershell_remote_services_add_trustedhost.yml

name: Powershell Remote Services Add TrustedHost
id: bef21d24-297e-45e3-9b9a-c6ac45450474
version: 1
date: '2023-11-23'
author: Teoderick Contreras, Splunk
status: production
type: TTP
data_source:
- Powershell Script Block Logging 4104
description: The following analytic identifies a suspicious PowerShell script execution via EventCode 4104 
  that contains command to add or modify the trustedhost configuration in Windows OS. 
  This behavior raises concerns due to the nature of modifications made to the 'TrustedHost' configuration, 
  which typically involves adjusting settings crucial for remote connections and security protocols. 
  Alterations in this area could potentially indicate attempts to manipulate trusted hosts or systems 
  for unauthorized remote access, a tactic commonly observed in various unauthorized access or compromise attempts.
search: '`powershell` EventCode=4104  ScriptBlockText = "*WSMan:\\localhost\\Client\\TrustedHosts*" ScriptBlockText IN ("* -Value *", "* -Concatenate *")
  | rename Computer as dest, UserID as user
  | stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText dest user
  | `security_content_ctime(firstTime)` 
  | `security_content_ctime(lastTime)` 
  | `powershell_remote_services_add_trustedhost_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: user and network administrator may used this function to add trusted host.
references:
- https://malpedia.caad.fkie.fraunhofer.de/details/win.darkgate
tags:
  analytic_story:
  - DarkGate Malware
  asset_type: Endpoint
  confidence: 80
  impact: 80
  message: a powershell script adding a remote trustedhost on $dest$ .
  mitre_attack_id:
  - T1021.006
  - T1021
  observable:
  - name: dest
    type: Hostname
    role:
    - Victim
  - name: user
    type: User
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  risk_score: 64
  required_fields:
  - _time
  - EventCode
  - ScriptBlockText
  - Computer
  - UserID
  - Score
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1021.006/wsman_trustedhost/wsman_pwh.log
    source: XmlWinEventLog:Microsoft-Windows-PowerShell/Operational
    sourcetype: XmlWinEventLog