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Description

The following analytic detects modifications to the BootExecute registry key, which manages applications and services executed during system boot. It leverages data from the Endpoint.Registry data model, focusing on changes to the registry path "HKLM\System\CurrentControlSet\Control\Session Manager\BootExecute". This activity is significant because unauthorized changes to this key can indicate attempts to achieve persistence, load malicious code, or tamper with the boot process. If confirmed malicious, this could allow an attacker to maintain persistence, execute arbitrary code at boot, or disrupt system operations.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2024-05-29
  • Author: Michael Haag, Splunk
  • ID: eabbac3a-45aa-4659-920f-6b8cff383fb8

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1542 Pre-OS Boot Defense Evasion, Persistence
T1547.001 Registry Run Keys / Startup Folder Persistence, Privilege Escalation
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="HKLM\\System\\CurrentControlSet\\Control\\Session Manager\\BootExecute" BY _time span=1h Registry.dest Registry.registry_path Registry.registry_key_name Registry.registry_value_name Registry.registry_value_data Registry.process_guid, Registry.action 
| `drop_dm_object_name(Registry)` 
| where isnotnull(registry_value_data) 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)`
| `windows_registry_bootexecute_modification_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_registry_bootexecute_modification_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_path
  • Registry.registry_key_name
  • Registry.registry_value_name
  • Registry.registry_value_data
  • Registry.process_guid
  • Registry.action

How To Implement

To successfully implement this search you need to be ingesting information on Windows Registry that include the name of the path and key responsible for the changes from your endpoints into the Endpoint datamodel in the Registry node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.

Known False Positives

False positives may be present and will need to be filtered.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
100.0 100 100 The Registry BootExecute value was modified on $dest$ and should be reviewed immediately.

: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: 2