Detection: Detect WMI Event Subscription Persistence

REMOVED DETECTION

This detection has been removed from the Splunk Threat Research content library and is no longer maintained or supported.

Reason: This rule uses only Sysmon EventID 20, which records creation of a WMI event consumer but does not confirm that a filter is bound to it. The Sysmon permanent subscription detection covers the binding with EventID 21.

Removed in version: 6.10.0

Replacement: WMI Permanent Event Subscription - Sysmon

If you have any questions or concerns, please reach out to us at research@splunk.com.

Created: 2021-06-16 Last Updated: 2026-10-23 ID: 01d9a0c2-cece-11eb-ab46-acde48001122 Author: Michael Haag, Splunk Type: TTP Product: Splunk Enterprise Security

Description

The following analytic identifies the creation of WMI Event Subscriptions, which can be used to establish persistence or perform privilege escalation. It detects EventID 19 (EventFilter creation), EventID 20 (EventConsumer creation), and EventID 21 (FilterToConsumerBinding creation) from Sysmon logs. This activity is significant because WMI Event Subscriptions can execute code with elevated SYSTEM privileges, making it a powerful persistence mechanism. If confirmed malicious, an attacker could maintain long-term access, escalate privileges, and execute arbitrary code, posing a severe threat to the environment.

Search

 1`sysmon` EventID=20
 2  
 3| stats count min(_time) as firstTime max(_time) as lastTime
 4    BY dest dvc object
 5       object_category object_path signature
 6       signature_id src status
 7       user user_id vendor_product
 8  
 9| `security_content_ctime(firstTime)`
10  
11| `security_content_ctime(lastTime)`
12  
13| `detect_wmi_event_subscription_persistence_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 20	Windows	`'XmlWinEventLog'`	`'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'`

Macros Used

Name	Value
sysmon	`(source=WinEventLog:Microsoft-Windows-Sysmon/Operational OR source=XmlWinEventLog:Microsoft-Windows-Sysmon/Operational OR source=Syslog:Linux-Sysmon/Operational)`
detect_wmi_event_subscription_persistence_filter	``

detect_wmi_event_subscription_persistence_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

Default Configuration

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

Setting	Value
Disabled	true
Cron Schedule	`N/A`
Earliest Time	`N/A`
Latest Time	`N/A`
Schedule Window	`N/A`
Creates Finding (Notable)	No
Creates Intermediate Finding (Risk Event)	No

TTP detections generate a Finding (Notable) and may generate Intermediate Findings (Risk Events) for associated entities.

Implementation

To successfully implement this search, you need to be ingesting logs with that provide WMI Event Subscription from your endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the Sysmon TA and have enabled EventID 19, 20 and 21. Tune and filter known good to limit the volume.

Known False Positives

It is possible some applications will create a consumer and may be required to be filtered. For tuning, add any additional LOLBin's for further depth of coverage.

Associated Analytic Story

No associated analytic story

References

Detection Testing

Test Type	Status	Dataset	Source	Sourcetype
Validation	Not Applicable	N/A	N/A	N/A
Unit	Not Applicable	N/A	`N/A`	`N/A`
Integration	Not Applicable	N/A	`N/A`	`N/A`

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: 13