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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.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2024-05-18
  • Author: Steven Dick, David Dorsey, Teoderick Contreras, Splunk
  • ID: c9f4b923-f8af-4155-b697-1354f5bcbc5e

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1546.012 Image File Execution Options Injection Privilege Escalation, Persistence
T1546 Event Triggered Execution Privilege Escalation, Persistence
Kill Chain Phase
  • Exploitation
  • Installation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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| 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 
| `drop_dm_object_name(Registry)` 
| where isnotnull(registry_value_data) 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `registry_keys_used_for_privilege_escalation_filter`

Macros

The SPL above uses the following Macros:

:information_source: registry_keys_used_for_privilege_escalation_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • Registry.dest
  • Registry.registry_value_name
  • Registry.registry_key_name
  • Registry.registry_path
  • Registry.registry_value_data
  • Registry.process_guid

How To Implement

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

RBA

Risk Score Impact Confidence Message
76.0 80 95 A registry activity in $registry_path$ related to privilege escalation in host $dest$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

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 | version: 8