Disabling Windows Local Security Authority Defences via Registry

name: Disabling Windows Local Security Authority Defences via Registry
id: 45cd08f8-a2c9-4f4e-baab-e1a0c624b0ab
version: 9
date: '2026-03-10'
author: Dean Luxton,Teoderick Contreras Splunk
status: production
type: TTP
data_source:
    - Sysmon EventID 13
description: The following analytic identifies the deletion of registry keys that disable Local Security Authority (LSA) protection and Microsoft Defender Device Guard. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on registry actions and paths associated with LSA and Device Guard settings. This activity is significant because disabling these defenses can leave a system vulnerable to various attacks, including credential theft and unauthorized code execution. If confirmed malicious, this action could allow attackers to bypass critical security mechanisms, leading to potential system compromise and persistent access.
search: '| tstats `security_content_summariesonly` min(_time) as _time from datamodel=Endpoint.Registry where Registry.registry_path IN ("*\\Lsa\\LsaCfgFlags", "*\\Lsa\\RunAsPPL", "*\\SOFTWARE\\Policies\\Microsoft\\Windows\\DeviceGuard\\*") AND ((Registry.action = deleted) OR (Registry.action = modified AND Registry.registry_value_data IN(0x00000000, 0))) 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)` | `disabling_windows_local_security_authority_defences_via_registry_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: Potential to be triggered by an administrator disabling protections for troubleshooting purposes.
references:
    - https://docs.microsoft.com/en-us/windows-server/security/credentials-protection-and-management/configuring-additional-lsa-protection
    - https://docs.microsoft.com/en-us/windows/security/identity-protection/credential-guard/credential-guard-manage
drilldown_searches:
    - name: View the detection results for - "$user$" and "$dest$"
      search: '%original_detection_search% | search  user = "$user$" dest = "$dest$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$user$" and "$dest$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$user$", "$dest$") 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: $info_max_time$
rba:
    message: An attempt to disable Windows LSA defences was detected on $dest$. The reg key $registry_path$ was deleted by $user$.
    risk_objects:
        - field: user
          type: user
          score: 50
        - field: dest
          type: system
          score: 50
    threat_objects: []
tags:
    analytic_story:
        - Windows Defense Evasion Tactics
        - Windows Registry Abuse
    asset_type: Endpoint
    mitre_attack_id:
        - T1556
    product:
        - Splunk Enterprise
        - Splunk Enterprise Security
        - Splunk Cloud
    security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1556/disable_lsa_protection_new/lsa_reg_deletion_modification.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog