Detection: Registry Keys Used For Privilege Escalation

Description

The following analytic detects modifications to registry keys under "Image File Execution Options" that can be used for privilege escalation. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to registry paths and values like GlobalFlag and Debugger. This activity is significant because attackers can use these modifications to intercept executable calls and attach malicious binaries to legitimate system binaries. If confirmed malicious, this could allow attackers to execute arbitrary code with elevated privileges, leading to potential system compromise and persistent access.

Search

1
2| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry WHERE ((Registry.registry_path="*Microsoft\\Windows NT\\CurrentVersion\\Image File Execution Options*") AND (Registry.registry_value_name=GlobalFlag OR Registry.registry_value_name=Debugger)) BY _time span=1h Registry.dest Registry.user Registry.registry_path Registry.registry_key_name Registry.registry_value_name Registry.registry_value_data Registry.process_guid 
3| `drop_dm_object_name(Registry)` 
4| where isnotnull(registry_value_data) 
5| `security_content_ctime(firstTime)` 
6| `security_content_ctime(lastTime)` 
7| `registry_keys_used_for_privilege_escalation_filter`

Data Source

Name	Platform	Sourcetype	Source
Sysmon EventID 12	Windows	'xmlwineventlog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'
Sysmon EventID 13	Windows	'xmlwineventlog'	'XmlWinEventLog:Microsoft-Windows-Sysmon/Operational'

Macros Used

Annotations

Default Configuration

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

Implementation

To successfully implement this search, you need to be ingesting logs with the registry value name, registry path, and registry value data from your endpoints. If you are using Sysmon, you must have at least version 2.0 of the offical Sysmon TA. https://splunkbase.splunk.com/app/5709

Known False Positives

There are many legitimate applications that must execute upon system startup and will use these registry keys to accomplish that task.

Associated Analytic Story

• Cloud Federated Credential Abuse

• Data Destruction

• Hermetic Wiper

• Suspicious Windows Registry Activities

• Windows Privilege Escalation

• Windows Registry Abuse

Risk Based Analytics (RBA)

References

• https://blog.malwarebytes.com/101/2015/12/an-introduction-to-image-file-execution-options/

Detection Testing

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: 9