Detection: Windows Compatibility Telemetry Tampering Through Registry

Updated Date: 2025-02-13 ID: 43834687-cc48-4878-a2fa-f76e4271791f Author: Steven Dick Type: TTP Product: Splunk Enterprise Security

Description

This detection identifies suspicious modifications to the Windows Compatibility Telemetry registry settings, specifically within the "TelemetryController" registry key and "Command" registry value. It leverages data from the Endpoint.Registry data model, focusing on registry paths and values indicative of such changes. 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.

 1
 2| tstats `security_content_summariesonly` min(_time) as firstTime, max(_time) as lastTime, count FROM datamodel=Endpoint.Registry WHERE (Registry.registry_path = "*\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\AppCompatFlags\\TelemetryController*" AND Registry.registry_value_name="Command" NOT Registry.registry_value_data IN ("(empty)")) BY Registry.dest Registry.user Registry.registry_path Registry.registry_key_name Registry.registry_value_name Registry.registry_value_data Registry.process_guid
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 4| `drop_dm_object_name(Registry)`
 5
 6| eval process = registry_value_data 
 7
 8| `security_content_ctime(firstTime)` 
 9
10| `security_content_ctime(lastTime)`
11
12| `windows_compatibility_telemetry_tampering_through_registry_filter`

Data Source

Name Platform Sourcetype Source
Sysmon EventID 13 Windows icon Windows 'xmlwineventlog' 'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'

Macros Used

Name Value
security_content_ctime convert timeformat="%Y-%m-%dT%H:%M:%S" ctime($field$)
windows_compatibility_telemetry_tampering_through_registry_filter search *
windows_compatibility_telemetry_tampering_through_registry_filter is an empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Annotations

- MITRE ATT&CK
+ Kill Chain Phases
+ NIST
+ CIS
- Threat Actors
ID Technique Tactic
T1546 Event Triggered Execution Persistence
T1053.005 Scheduled Task Privilege Escalation
Exploitation
Installation
DE.CM
CIS 10

Default Configuration

This detection is configured by default in Splunk Enterprise Security to run with the following settings:

Setting Value
Disabled true
Cron Schedule 0 * * * *
Earliest Time -70m@m
Latest Time -10m@m
Schedule Window auto
Creates Notable Yes
Rule Title %name%
Rule Description %description%
Notable Event Fields user, dest
Creates Risk Event True
This configuration file applies to all detections of type TTP. These detections will use Risk Based Alerting and generate Notable Events.

Implementation

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

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

The process $process$ was added to registry settings for the Compatibility Appraiser by $user$ on host $dest$

Risk Object Risk Object Type Risk Score Threat Objects
user user 70 process
dest system 70 process

References

Detection Testing

Test Type Status Dataset Source Sourcetype
Validation ✅ Passing N/A N/A N/A
Unit ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational XmlWinEventLog
Integration ✅ Passing Dataset XmlWinEventLog:Microsoft-Windows-Sysmon/Operational XmlWinEventLog

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

Source: GitHub | Version: 2