Detection rules › Splunk
Windows Registry BootExecute Modification
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.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | T1542 Pre-OS Boot, T1547.001 Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder |
| Privilege Escalation | T1547.001 Boot or Logon Autostart Execution: Registry Run Keys / Startup Folder |
| Stealth | T1542 Pre-OS Boot |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 13 | RegistryEvent (Value Set) |
Rule body splunk
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/
drilldown_searches:
- name: View the detection results for - "$dest$"
search: '%original_detection_search% | search dest = "$dest$"'
earliest_offset: $info_min_time$
latest_offset: $info_max_time$
- name: View risk events for the last 7 days for - "$dest$"
search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
earliest_offset: 7d
latest_offset: "0"
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
tests:
- name: True Positive Test
attack_data:
- data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1547.001/atomic_red_team/bootexecute-windows-sysmon.log
source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
sourcetype: XmlWinEventLog
test_type: unit
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
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
| Field | Kind | Values |
|---|---|---|
Registry.registry_path | eq |
|
registry_value_data | is_not_null |