Name:Windows Compatibility Telemetry Suspicious Child Process id:56fe46ca-ffef-46fe-8f0e-5cd4b7b4cc0c version:2 date:2025-02-13 author:Steven Dick status:production type:TTP Description:The following analytic detects the execution of CompatTelRunner.exe with parameters indicative of a process not part of the normal "Microsoft Compatibility Appraiser" telemetry collection. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on process names, parent processes, and command-line arguments. This activity is significant because CompatTelRunner.exe and the "Microsoft Compatibility Appraiser" task always run as System and can be used to elevate privileges or establish a highly privileged persistence mechanism. If confirmed malicious, this could enable unauthorized code execution, privilege escalation, or persistent access to the compromised system. Data_source:
-Windows Event Log Security 4688
-Sysmon EventID 1
-CrowdStrike ProcessRollup2
search:| tstats `security_content_summariesonly` values(Processes.parent_process) as Processes.parent_process, values(Processes.process) as Processes.process values(Processes.process_current_directory) AS process_current_directory, values(Processes.process_id) as Processes.process_id, values(Processes.process_guid) as Processes.process_guid, count min(_time) AS firstTime, max(_time) AS lastTime FROM datamodel=Endpoint.Processes where Processes.parent_process_name = "CompatTelRunner.exe" AND Processes.process="* -cv:*" NOT Processes.process IN ("* -m:*") BY _time span=1h Processes.user Processes.dest Processes.parent_process_name Processes.process_name |`drop_dm_object_name(Processes)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_compatibility_telemetry_suspicious_child_process_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:None identified References: -https://attack.mitre.org/techniques/T1546/ -https://scythe.io/threat-thursday/windows-telemetry-persistence -https://www.trustedsec.com/blog/abusing-windows-telemetry-for-persistence drilldown_searches: name:'View the detection results for - "$dest$"' search:'%original_detection_search% | search dest = "$dest$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' name:'View risk events for the last 7 days for - "$dest$"' search:'| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") 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:'$info_max_time$' name:'Investigate processes on $dest$' search:'| from datamodel Endpoint.Processes | search dest = "$dest$" AND process_name = "$process_name$"' earliest_offset:'$info_min_time$' latest_offset:'$info_max_time$' tags: analytic_story: - 'Windows Persistence Techniques' asset_type:Endpoint mitre_attack_id: - 'T1546' - 'T1053.005' product: - 'Splunk Enterprise' - 'Splunk Enterprise Security' - 'Splunk Cloud' security_domain:endpoint
