Windows Identify Protocol Handlers

Name:Windows Identify Protocol Handlers
id:bd5c311e-a6ea-48ae-a289-19a3398e3648
version:5
date:2024-10-17
author:Michael Haag, Splunk
status:production
type:Hunting
Description:The following analytic identifies the use of protocol handlers executed via the command line. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and command-line telemetry. This activity is significant because protocol handlers can be exploited to execute arbitrary commands or launch applications, potentially leading to unauthorized actions. If confirmed malicious, an attacker could use this technique to gain code execution, escalate privileges, or maintain persistence within the environment, posing a significant security risk.
Data_source:

• -Sysmon EventID 1
• -Windows Event Log Security 4688
• -CrowdStrike ProcessRollup2

search:| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime values(Processes.process) as process values(Processes.parent_process) as parent_process from datamodel=Endpoint.Processes by Processes.dest Processes.parent_process_name Processes.user Processes.process_name Processes.process
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `drop_dm_object_name(Processes)`
| lookup windows_protocol_handlers handler AS process OUTPUT handler ishandler
| where ishandler="TRUE"
| `windows_identify_protocol_handlers_filter`

how_to_implement:The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives:False positives will be found. https and http is a URL Protocol handler that will trigger this analytic. Tune based on process or command-line.
References:
  -https://gist.github.com/MHaggis/a0d3edb57d36e0916c94c0a464b2722e
  -https://www.oreilly.com/library/view/learning-java/1565927184/apas02.html
  -https://blogs.windows.com/msedgedev/2022/01/20/getting-started-url-protocol-handlers-microsoft-edge/
  -https://github.com/Mr-Un1k0d3r/PoisonHandler
  -https://www.mdsec.co.uk/2021/03/phishing-users-to-take-a-test/
  -https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1218/T1218.md#atomic-test-5---protocolhandlerexe-downloaded-a-suspicious-file
  -https://techcommunity.microsoft.com/t5/windows-it-pro-blog/disabling-the-msix-ms-appinstaller-protocol-handler/ba-p/3119479
  -https://www.huntress.com/blog/microsoft-office-remote-code-execution-follina-msdt-bug
  -https://parsiya.net/blog/2021-03-17-attack-surface-analysis-part-2-custom-protocol-handlers/
drilldown_searches:
  :
tags:
  analytic_story:
    - 'Living Off The Land'
  asset_type:Endpoint
  confidence:20
  impact:30
  message:An instance of $parent_process_name$ spawning $process_name$ was identified on endpoint $dest$ by user $user$ utilizing a protocol handler.
  mitre_attack_id:
    - 'T1059'
  observable:
    name:'user'
    type:'User'
    - role:
      - 'Victim'
    name:'dest'
    type:'Endpoint'
    - role:
      - 'Victim'
    name:'parent_process_name'
    type:'Process Name'
    - role:
      - 'Attacker'
    name:'process_name'
    type:'Process'
    - role:
      - 'Attacker'
  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:6
  security_domain:endpoint

tests:
 name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1059/protocol_handlers/protocolhandlers.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
  update_timestamp: True
manual_test:None