Detection rules › Splunk

Windows Service Deletion In Registry

Status
production
Severity
low
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
Teoderick Contreras, Splunk
Source
github.com/splunk/security_content

The following analytic detects the deletion of a service from the Windows Registry under CurrentControlSet\Services. It leverages data from the Endpoint.Registry datamodel, specifically monitoring registry paths and actions related to service deletion. This activity is significant as adversaries may delete services to evade detection and hinder incident response efforts. If confirmed malicious, this action could disrupt legitimate services, impair system functionality, and potentially allow attackers to maintain a lower profile within the environment, complicating detection and remediation efforts.

MITRE ATT&CK coverage

TacticTechniques
ImpactT1489 Service Stop

Event coverage

ProviderEventTitle
SysmonEvent ID 13RegistryEvent (Value Set)

Rule body splunk

name: Windows Service Deletion In Registry
id: daed6823-b51c-4843-a6ad-169708f1323e
version: 10
creation_date: '2022-06-22'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: The following analytic detects the deletion of a service from the Windows Registry under CurrentControlSet\Services. It leverages data from the Endpoint.Registry datamodel, specifically monitoring registry paths and actions related to service deletion. This activity is significant as adversaries may delete services to evade detection and hinder incident response efforts. If confirmed malicious, this action could disrupt legitimate services, impair system functionality, and potentially allow attackers to maintain a lower profile within the environment, complicating detection and remediation efforts.
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\\Services*" AND (Registry.action = deleted OR (Registry.registry_value_name = DeleteFlag AND Registry.registry_value_data = 0x00000001 AND Registry.action=modified)) 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)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_service_deletion_in_registry_filter`'
how_to_implement: To successfully implement this search you need to be ingesting information on process that include the name of the process responsible for the changes from your endpoints into the `Endpoint` datamodel in the `Registry` node. Also make sure that this registry was included in your config files ex. sysmon config to be monitored.
known_false_positives: This event can be seen when administrator delete a service or uninstall/reinstall a software that creates service entry, but it is still recommended to check this alert with high priority.
references:
    - https://unit42.paloaltonetworks.com/brute-ratel-c4-tool/
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"
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: A service was deleted on $dest$ within the Windows registry.
analytic_story:
    - PlugX
    - Crypto Stealer
    - Brute Ratel C4
asset_type: Endpoint
mitre_attack_id:
    - T1489
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/malware/brute_ratel/service_deletion/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\\Services*" AND (Registry.action = deleted OR (Registry.registry_value_name = DeleteFlag AND Registry.registry_value_data = 0x00000001 AND Registry.action=modified)) 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: search

| `security_content_ctime(firstTime)`

Stage 4: search

| `security_content_ctime(lastTime)`

Stage 5: search

| `windows_service_deletion_in_registry_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.

FieldKindValues
Registry.actioneq
  • deleted corpus 8 (splunk 8)
  • modified corpus 6 (splunk 6)
Registry.registry_patheq
  • "*\\SYSTEM\\CurrentControlSet\\Services*" corpus 2 (splunk 2)
Registry.registry_value_dataeq
  • 0x00000001 corpus 63 (splunk 54, elastic 9)
Registry.registry_value_nameeq
  • DeleteFlag