Detection rules › Splunk

Windows Registry BootExecute Modification

Status
production
Severity
medium
Group by
TargetObject, computer_name, details, event_type, process_guid, process_id, registry_hive, registry_path, registry_status, registry_value_name, registry_value_type, user, vendor_product
Author
Michael Haag, Teoderick Contreras, Splunk
Source
github.com/splunk/security_content

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.

Known false positives

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

MITRE ATT&CK coverage

Telemetry coverage

Rule body

name: Windows Registry BootExecute Modification
id: eabbac3a-45aa-4659-920f-6b8cff383fb8
version: 12
creation_date: '2023-05-11'
modification_date: '2026-05-13'
author: Michael Haag, Teoderick Contreras, Splunk
status: production
type: TTP
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.
data_source:
    - Sysmon EventID 13
search: '| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry WHERE Registry.registry_path="*\\System\\CurrentControlSet\\Control\\Session Manager\\BootExecute" by Registry.action Registry.dest Registry.process_guid Registry.process_id Registry.registry_hive Registry.registry_path Registry.registry_key_name Registry.registry_value_data Registry.registry_value_name Registry.registry_value_type Registry.status Registry.user Registry.vendor_product | `drop_dm_object_name(Registry)` | where isnotnull(registry_value_data) | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`| `windows_registry_bootexecute_modification_filter`'
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.
references:
    - https://www.microsoft.com/en-us/security/blog/2023/04/11/guidance-for-investigating-attacks-using-cve-2022-21894-the-blacklotus-campaign/
finding:
    title: The Registry BootExecute value was modified on $dest$ and should be reviewed immediately.
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - Windows BootKits
asset_type: Endpoint
mitre_attack_id:
    - T1542
    - T1547.001
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint

Stages and Predicates

Stage 1: tstats

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime FROM datamodel=Endpoint.Registry WHERE Registry.registry_path="*\\System\\CurrentControlSet\\Control\\Session Manager\\BootExecute" by Registry.action Registry.dest Registry.process_guid Registry.process_id Registry.registry_hive Registry.registry_path Registry.registry_key_name Registry.registry_value_data Registry.registry_value_name Registry.registry_value_type Registry.status Registry.user Registry.vendor_product

Stage 2: search

| `drop_dm_object_name(Registry)`

Stage 3: where

| where isnotnull(registry_value_data)

Stage 4: search

| `security_content_ctime(firstTime)`

Stage 5: search

| `security_content_ctime(lastTime)`

Stage 6: search

| `windows_registry_bootexecute_modification_filter`

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Registry.registry_patheq
  • "*\\System\\CurrentControlSet\\Control\\Session Manager\\BootExecute"
field:"registry_path" kind:eq
registry_value_datais_not_null
  • (no value, null check)
field:"Details" kind:is_not_null