Detection: Windows CrowdStrike Agent Registry Key Removal

Updated Date: 2026-04-13 ID: 094e8c62-c071-4b3d-af43-d3c74c4b249f Author: Raven Tait, Splunk Type: Anomaly Product: Splunk Enterprise Security

Description

Detects delete events on the CrowdStrike registry keys. These keys are removed as part of the agent uninstallation process. This activity should only occur during planned events and any instances outside that should be evaluated for malicious activity such as CVE-2022-44721.

Search

 1`sysmon`
 2EventID="12"
 3TargetObject="*\\SYSTEM\\CrowdStrike"
 4action="deleted"
 5
 6| fillnull
 7
 8| stats count min(_time) as firstTime
 9              max(_time) as lastTime
10  by Computer EventID TargetObject action dest process_guid process_id registry_hive
11     registry_path registry_key_name status user vendor_product
12
13
14| `security_content_ctime(firstTime)`
15
16| `security_content_ctime(lastTime)`
17
18| `windows_crowdstrike_agent_registry_key_removal_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 12	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_crowdstrike_agent_registry_key_removal_filter	`search *`

windows_crowdstrike_agent_registry_key_removal_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
T1685	Disable or Modify Tools	Defense Impairment

Exploitation

DE.AE

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 Risk Event	True

This configuration file applies to all detections of type anomaly. These detections will use Risk Based Alerting.

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

Agent uninstallations during planned maintenance or legitimate IT workflows may trigger these detections. Review such events to avoid false positive alerts.

Associated Analytic Story

Risk Based Analytics (RBA)

Risk Message:

Potential removal of CrowdStrike agent activity observed on $dest$ via $TargetObject$.

Risk Object	Risk Object Type	Risk Score	Threat Objects
dest	system	20	No Threat Objects

References

https://github.com/purplededa/CVE-2022-44721-CsFalconUninstaller

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: 1