Detection rules › Splunk

Windows Modify Registry DisableSecuritySettings

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 that disable security settings for Terminal Services. It leverages the Endpoint data model, specifically monitoring changes to the registry path associated with Terminal Services security settings. This activity is significant because altering these settings can weaken the security posture of Remote Desktop Services, potentially allowing unauthorized remote access. If confirmed malicious, such modifications could enable attackers to gain persistent remote access to the system, facilitating further exploitation and data exfiltration.

Known false positives

  • Administrators may enable or disable this feature that may cause some false positive, however is not common. Filter as needed.

MITRE ATT&CK coverage

TacticTechniques
Persistence
Defense Impairment

Telemetry coverage

Rule body

name: Windows Modify Registry DisableSecuritySettings
id: 989019b4-b7aa-418a-9a17-2293e91288b6
version: 11
creation_date: '2022-07-06'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: TTP
description: The following analytic detects modifications to the Windows registry that disable security settings for Terminal Services. It leverages the Endpoint data model, specifically monitoring changes to the registry path associated with Terminal Services security settings. This activity is significant because altering these settings can weaken the security posture of Remote Desktop Services, potentially allowing unauthorized remote access. If confirmed malicious, such modifications could enable attackers to gain persistent remote access to the system, facilitating further exploitation and data exfiltration.
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 = "*\\Terminal Services\\DisableSecuritySettings"  Registry.registry_value_data = 0x00000001 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_modify_registry_disablesecuritysettings_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: Administrators may enable or disable this feature that may cause some false positive, however is not common. Filter as needed.
references:
    - https://malpedia.caad.fkie.fraunhofer.de/details/win.darkgate
finding:
    title: the registry for terminal services settings was modified to disable security settings on $dest$.
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - DarkGate Malware
    - CISA AA23-347A
asset_type: Endpoint
mitre_attack_id:
    - T1112
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 = "*\\Terminal Services\\DisableSecuritySettings"  Registry.registry_value_data = 0x00000001 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_modify_registry_disablesecuritysettings_filter`

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Registry.registry_patheq
  • "*\\Terminal Services\\DisableSecuritySettings"
field:"registry_path" kind:eq
Registry.registry_value_dataeq
  • 0x00000001 corpus 61 (splunk 52, elastic 9)
field:"Details" kind:eq value:"0x00000001"