Remote Process Instantiation via WMI and PowerShell Script Block

Original Source: [splunk source]
Name:Remote Process Instantiation via WMI and PowerShell Script Block
id:2a048c14-4634-11ec-a618-3e22fbd008af
version:4
date:2024-09-30
author:Mauricio Velazco, Splunk
status:production
type:TTP
Description:The following analytic detects the execution of the `Invoke-WmiMethod` commandlet with parameters used to start a process on a remote endpoint via WMI, leveraging PowerShell Script Block Logging (EventCode=4104). This method identifies specific script block text patterns associated with remote process instantiation. This activity is significant as it may indicate lateral movement or remote code execution attempts by adversaries. If confirmed malicious, this could allow attackers to execute arbitrary code on remote systems, potentially leading to further compromise and persistence within the network.
Data_source:
  • -Powershell Script Block Logging 4104
search:`powershell` EventCode=4104 ScriptBlockText="*Invoke-WmiMethod*" AND (ScriptBlockText="*-CN*" OR ScriptBlockText="*-ComputerName*") AND ScriptBlockText="*-Class Win32_Process*" AND ScriptBlockText="*-Name create*"
| stats count min(_time) as firstTime max(_time) as lastTime by EventCode ScriptBlockText Computer UserID| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `remote_process_instantiation_via_wmi_and_powershell_script_block_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 instructions can be found https://docs.splunk.com/Documentation/UBA/5.0.4.1/GetDataIn/AddPowerShell#Configure_module_logging_for_PowerShell.
known_false_positives:Administrators may leverage WWMI and powershell.exe to start a process on remote systems, but this activity is usually limited to a small set of hosts or users.
References:
  -https://attack.mitre.org/techniques/T1047/
  -https://docs.microsoft.com/en-us/powershell/module/microsoft.powershell.management/invoke-wmimethod?view=powershell-5.1
drilldown_searches:
name:'View the detection results for - "$Computer$"'
search:'%original_detection_search% | search Computer = "$Computer$"'
earliest_offset:'$info_min_time$'
latest_offset:'$info_max_time$'
name:'View risk events for the last 7 days for - "$Computer$"'
search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$Computer$") starthoursago=168 | 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:'$info_min_time$'
latest_offset:'$info_max_time$'
tags:
  analytic_story:
    - 'Active Directory Lateral Movement'
  asset_type:Endpoint
  confidence:70
  impact:90
  message:A process was started on a remote endpoint from $Computer$ by abusing WMI using PowerShell.exe
  mitre_attack_id:
    - 'T1047'
  observable:
    name:'Computer'
    type:'Endpoint'
    - role:
      - 'Victim'
  product:
    - 'Splunk Enterprise'
    - 'Splunk Enterprise Security'
    - 'Splunk Cloud'
  required_fields:
    - '_time'
    - 'EventCode'
    - 'Message'
    - 'Computer'
    - 'UserID'
  risk_score:63
  security_domain:endpoint

tests:
name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1047/lateral_movement/wmi_remote_process_powershell.log
  source: XmlWinEventLog:Microsoft-Windows-PowerShell/Operational
  sourcetype: XmlWinEventLog
manual_test:None

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