Windows Registry Certificate Added

name: Windows Registry Certificate Added
id: 5ee98b2f-8b9e-457a-8bdc-dd41aaba9e87
version: 10
date: '2026-03-10'
author: Michael Haag, Teodeerick Contreras, Splunk
status: production
type: Anomaly
description: The following analytic detects the installation of a root CA certificate by monitoring specific registry paths for SetValue events. It leverages data from the Endpoint datamodel, focusing on registry paths containing "certificates" and registry values named "Blob." This activity is significant because unauthorized root CA certificates can compromise the integrity of encrypted communications and facilitate man-in-the-middle attacks. If confirmed malicious, this could allow an attacker to intercept, decrypt, or manipulate sensitive data, leading to severe security breaches.
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 IN ("*\\certificates\\*") AND Registry.registry_value_name="Blob" 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_registry_certificate_added_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 `Processes` and `Registry` node. In addition, confirm the latest CIM App 4.20 or higher is installed and the latest TA for the endpoint product.
known_false_positives: False positives will be limited to a legitimate business applicating consistently adding new root certificates to the endpoint. Filter by user, process, or thumbprint.
references:
    - https://posts.specterops.io/code-signing-certificate-cloning-attacks-and-defenses-6f98657fc6ec
    - https://github.com/redcanaryco/atomic-red-team/tree/master/atomics/T1553.004
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: $info_max_time$
rba:
    message: A root certificate was added on $dest$.
    risk_objects:
        - field: dest
          type: system
          score: 20
    threat_objects: []
tags:
    analytic_story:
        - Windows Drivers
        - Windows Registry Abuse
    asset_type: Endpoint
    mitre_attack_id:
        - T1553.004
    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/T1587.002/atomic_red_team/certblob_windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog