Windows Modify Registry DisableRemoteDesktopAntiAlias

Original Source: [splunk source]
Name:Windows Modify Registry DisableRemoteDesktopAntiAlias
id:4927c6f1-4667-42e6-bd7a-f5222116386b
version:3
date:2024-09-30
author:Teoderick Contreras, Splunk
status:production
type:TTP
Description:The following analytic detects modifications to the Windows registry key "DisableRemoteDesktopAntiAlias" with a value set to 0x00000001. This detection leverages data from the Endpoint datamodel, specifically monitoring changes in the Registry node. This activity is significant as it may indicate the presence of DarkGate malware, which alters this registry setting to enhance its remote desktop capabilities. If confirmed malicious, this modification could allow an attacker to maintain persistence and control over the compromised host, potentially leading to further exploitation and data exfiltration.
Data_source:
  • -Sysmon EventID 12
  • -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\\DisableRemoteDesktopAntiAlias" Registry.registry_value_data = 0x00000001 by Registry.registry_path Registry.registry_value_name Registry.registry_value_data Registry.process_guid Registry.action Registry.user Registry.dest
| `drop_dm_object_name(Registry)`
| `security_content_ctime(firstTime)`
| `security_content_ctime(lastTime)`
| `windows_modify_registry_disableremotedesktopantialias_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
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 ("$dest$") starthoursago=168 | 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:'$info_min_time$'
latest_offset:'$info_max_time$'
tags:
  analytic_story:
    - 'DarkGate Malware'
  asset_type:Endpoint
  confidence:70
  impact:70
  message:the registry for remote desktop settings was modified to be DisableRemoteDesktopAntiAlias on $dest$.
  mitre_attack_id:
    - 'T1112'
  observable:
    name:'dest'
    type:'Endpoint'
    - role:
      - 'Victim'
  product:
    - 'Splunk Enterprise'
    - 'Splunk Enterprise Security'
    - 'Splunk Cloud'
  risk_score:49
  required_fields:
    - '_time'
    - 'Registry.registry_key_name'
    - 'Registry.registry_path'
    - 'Registry.user'
    - 'Registry.dest'
    - 'Registry.registry_value_name'
    - 'Registry.action'
  security_domain:endpoint

tests:
name:'True Positive Test'
 attack_data:
  data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1112/DisableRemoteDesktopAntiAlias/disable_remote_alias.log
  source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
  sourcetype: XmlWinEventLog
manual_test:None

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