Detection rules › Splunk

Windows Modify Registry Disable Restricted Admin

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
Teoderick Contreras, Splunk
Source
github.com/splunk/security_content

The following analytic detects modifications to the Windows registry entry "DisableRestrictedAdmin," which controls the Restricted Admin mode behavior. This detection leverages registry activity logs from endpoint data sources like Sysmon or Carbon Black. Monitoring this activity is crucial as changes to this setting can disable a security feature that limits credential exposure during remote connections. If confirmed malicious, an attacker could weaken security controls, increasing the risk of credential theft and unauthorized access to sensitive systems.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1112 Modify Registry
Defense ImpairmentT1112 Modify Registry

Event coverage

ProviderEventTitle
SysmonEvent ID 13RegistryEvent (Value Set)

Rule body splunk

name: Windows Modify Registry Disable Restricted Admin
id: cee573a0-7587-48e6-ae99-10e8c657e89a
version: 13
creation_date: '2024-01-10'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: TTP
description: The following analytic detects modifications to the Windows registry entry "DisableRestrictedAdmin," which controls the Restricted Admin mode behavior. This detection leverages registry activity logs from endpoint data sources like Sysmon or Carbon Black. Monitoring this activity is crucial as changes to this setting can disable a security feature that limits credential exposure during remote connections. If confirmed malicious, an attacker could weaken security controls, increasing the risk of credential theft and unauthorized access to sensitive systems.
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\\Lsa\\DisableRestrictedAdmin" Registry.registry_value_data = 0x00000000) 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_modify_registry_disable_restricted_admin_filter`'
how_to_implement: To successfully implement this search, you must be ingesting data that records registry activity from your hosts to populate the endpoint data model in the registry node. This is typically populated via endpoint detection-and-response product, such as Carbon Black or endpoint data sources, such as Sysmon. The data used for this search is typically generated via logs that report reads and writes to the registry.
known_false_positives: Administrator may change this registry setting. Filter as needed.
references:
    - https://www.cisa.gov/news-events/cybersecurity-advisories/aa23-347a
drilldown_searches:
    - name: View the detection results for - "$dest$" and "$user$"
      search: '%original_detection_search% | search  dest = "$dest$" user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$" and "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$", "$user$") | 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: Windows Modify Registry Disable Restricted Admin on $dest$ by $user$.
    entity:
        field: user
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 50
          message: Windows Modify Registry Disable Restricted Admin on $dest$ by $user$.
analytic_story:
    - GhostRedirector IIS Module and Rungan Backdoor
    - Medusa Ransomware
    - CISA AA23-347A
asset_type: Endpoint
mitre_attack_id:
    - T1112
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/T1003.004/NoLMHash/lsa-reg-settings-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\\Lsa\\DisableRestrictedAdmin" Registry.registry_value_data = 0x00000000) 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_modify_registry_disable_restricted_admin_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.registry_patheq
  • "*\\System\\CurrentControlSet\\Control\\Lsa\\DisableRestrictedAdmin"
Registry.registry_value_dataeq
  • 0x00000000 corpus 43 (splunk 35, elastic 8)
registry_value_datais_not_null
  • (no value, null check)