Windows COM Hijacking InprocServer32 Modification

Original Source: [splunk source]
Name:Windows COM Hijacking InprocServer32 Modification
id:b7bd83c0-92b5-4fc7-b286-23eccfa2c561
version:9
date:2025-02-10
author:Michael Haag, Splunk
status:production
type:TTP
Description:The following analytic detects the modification of the InProcServer32 registry key by reg.exe, indicative of potential COM hijacking. This detection leverages data from Endpoint Detection and Response (EDR) agents, focusing on process and command-line execution logs. COM hijacking is significant as it allows adversaries to insert malicious code that executes in place of legitimate software, providing a means for persistence. If confirmed malicious, this activity could enable attackers to execute arbitrary code, disrupt legitimate system components, and maintain long-term access to the compromised environment.
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 from datamodel=Endpoint.Processes where `process_reg` Processes.process=*inprocserver32* by Processes.action Processes.dest Processes.original_file_name Processes.parent_process Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product
| `drop_dm_object_name(Processes)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_com_hijacking_inprocserver32_modification_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 may be present and some filtering may be required.
References:
  -https://attack.mitre.org/techniques/T1546/015/
  -https://blog.cluster25.duskrise.com/2022/09/23/in-the-footsteps-of-the-fancy-bear-powerpoint-graphite/
  -https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1546.015/T1546.015.md
drilldown_searches:
name:'View the detection results for - "$user$" and "$dest$"'
search:'%original_detection_search% | search user = "$user$" dest = "$dest$"'
earliest_offset:'$info_min_time$'
latest_offset:'$info_max_time$'
name:'View risk events for the last 7 days for - "$user$" and "$dest$"'
search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") 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:
    - 'Living Off The Land'
    - 'Compromised Windows Host'
  asset_type:Endpoint
  mitre_attack_id:
    - 'T1546.015'
  product:
    - 'Splunk Enterprise'
    - 'Splunk Enterprise Security'
    - 'Splunk Cloud'
  security_domain:endpoint

tests:
name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1546.015/atomic_red_team/windows-sysmon.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
manual_test:None