Detection rules › Splunk

Windows Computer Account Changed to Domain Controller

Status
production
Severity
medium
Group by
UserAccountControl, computer_name, signature_id, user
Author
Raven Tait, Splunk
Source
github.com/splunk/security_content

Detects a modification to the User Account Control flags for a computer account where the SERVER_TRUST_ACCOUNT flag is set. This flag is normally associated with domain controller computer accounts. This activity may indicate a legitimate domain controller promotion or, if unexpected, an attempt to grant a computer account domain controller-like trust within Active Directory.

MITRE ATT&CK coverage

TacticTechniques
PersistenceT1136.002 Create Account: Domain Account

Event coverage

Rule body splunk

name: Windows Computer Account Changed to Domain Controller
id: f9df6250-fa45-4f62-bc9a-768c60bf99b2
version: 2
creation_date: '2026-05-05'
modification_date: '2026-05-13'
author: Raven Tait, Splunk
status: production
type: TTP
description: |-
    Detects a modification to the User Account Control flags for a computer account where the `SERVER_TRUST_ACCOUNT` flag is set.
    This flag is normally associated with domain controller computer accounts.
    This activity may indicate a legitimate domain controller promotion or, if unexpected, an attempt to grant a computer account domain controller-like trust within Active Directory.
data_source:
    - Windows Event Log Security 4742
search: |-
    `wineventlog_security`
    EventID=4742
    UserAccountControl="*%%2088*"
    | fillnull
    | stats count min(_time) as firstTime
                  max(_time) as lastTime
      by Computer TargetUserName UserAccountControl EventID
    
    | rename Computer as dest
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_computer_account_changed_to_domain_controller_filter`
how_to_implement: The detection is based on data that originates from Endpoint Detection and Response (EDR) agents. These agents are designed to provide security-related telemetry from the endpoints where the agent is installed. To implement this search, you must ingest logs that contain the process GUID, process name, and parent process. Additionally, you must ingest complete command-line executions. These logs must be processed using the appropriate Splunk Technology Add-ons that are specific to the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint` data model. Use the Splunk Common Information Model (CIM) to normalize the field names and speed up the data modeling process.
known_false_positives: Some legitimate administrative activities during domain controller promotions or system updates may trigger this rule. Filter alerts originating from authorized IT personnel or approved change management processes.
references:
    - https://docs.microsoft.com/en-us/windows/security/threat-protection/auditing/event-4742
    - https://docs.microsoft.com/en-us/troubleshoot/windows-server/identity/useraccountcontrol-manipulate-account-properties
drilldown_searches:
    - earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
      name: View the detection results for - "$user$" and "$dest$"
      search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
    - name: View risk events for the last 7 days for - "$user$" and "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") | 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: Computer account User Account Control flags changed to domain controller $UserAccountControl$ on $dest$.
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - Active Directory Privilege Escalation
    - Sneaky Active Directory Persistence Tricks
asset_type: Endpoint
mitre_attack_id:
    - T1136.002
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/T1136.002/snapattack/snapattack.log
          source: XmlWinEventLog:Security
          sourcetype: XmlWinEventLog
      test_type: unit

Stages and Predicates

Stage 1: search

`wineventlog_security`
EventID=4742
UserAccountControl="*%%2088*"

Stage 2: fillnull

| fillnull

Stage 3: stats

| stats count min(_time) as firstTime
              max(_time) as lastTime
  by Computer TargetUserName UserAccountControl EventID

Stage 4: rename

| rename Computer as dest

Stage 5: search

| `security_content_ctime(firstTime)`

Stage 6: search

| `security_content_ctime(lastTime)`

Stage 7: search

| `windows_computer_account_changed_to_domain_controller_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
EventIDeq
  • 4742 corpus 6 (splunk 6)
UserAccountControleq
  • "*%%2088*"