Windows Outlook LoadMacroProviderOnBoot Persistence

name: Windows Outlook LoadMacroProviderOnBoot Persistence
id: 93c91139-01f8-4905-802b-0d106f026b13
version: 2
date: '2026-03-10'
author: Raven Tait, Splunk
status: production
type: TTP
description: The following analytic detects the modification of the Windows Registry key "LoadMacroProviderOnBoot" under Outlook. This enables automatic loading of macros, which could allow malicious scripts to run without notice. This detection leverages data from the Endpoint.Registry datamodel to search for this key being enabled. This activity is significant as it is commonly associated with some malware infections, indicating potential malicious intent to harvest email information.
data_source:
    - Sysmon EventID 13
search: '| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Registry WHERE Registry.registry_path="*\\Outlook\\*" Registry.registry_value_name="LoadMacroProviderOnBoot" 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_outlook_loadmacroprovideronboot_persistence_filter`'
how_to_implement: To successfully implement this search, you need to be ingesting logs with the registry value name, registry path, and registry value data from your endpoints. If you are using Sysmon, you must have at least version 2.0 of the official Sysmon TA. https://splunkbase.splunk.com/app/5709
known_false_positives: It is unusual to modify this feature on a Windows system. Although no false positives have been identified, use the provided filter macro to tune the search.
references:
    - https://lab52.io/blog/analyzing-notdoor-inside-apt28s-expanding-arsenal/
    - https://hackread.com/russian-apt28-notdoor-backdoor-microsoft-outlook/
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: Outlook LoadMacroProviderOnBoot registry key modified on $dest$
    risk_objects:
        - field: dest
          type: system
          score: 50
    threat_objects: []
tags:
    analytic_story:
        - NotDoor Malware
        - Windows Registry Abuse
    asset_type: Endpoint
    mitre_attack_id:
        - T1112
        - T1137
    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/malware/notdoor/loadmacroprovideronboot/windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog