Detection rules › Splunk

Windows Modify Registry Auto Update Notif

Status
production
Severity
low
Group by
TargetObject, computer_name, details, event_type, process_guid, process_id, registry_hive, registry_path, registry_status, registry_value_name, registry_value_type, user, vendor_product
Author
Teoderick Contreras, Splunk
Source
github.com/splunk/security_content

The following analytic detects a suspicious modification to the Windows registry that changes the auto-update notification setting to "Notify before download." This detection leverages data from the Endpoint.Registry data model, focusing on specific registry paths and values. This activity is significant because it is a known technique used by adversaries, including malware like RedLine Stealer, to evade detection and potentially deploy additional payloads. If confirmed malicious, this modification could allow attackers to bypass security measures, maintain persistence, and exploit vulnerabilities on the target host.

Known false positives

  • administrators may enable or disable this feature that may cause some false positive.

MITRE ATT&CK coverage

TacticTechniques
Persistence
Defense Impairment

Telemetry coverage

Rule body

name: Windows Modify Registry Auto Update Notif
id: 4d1409df-40c7-4b11-aec4-bd0e709dfc12
version: 11
creation_date: '2023-04-26'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: The following analytic detects a suspicious modification to the Windows registry that changes the auto-update notification setting to "Notify before download." This detection leverages data from the Endpoint.Registry data model, focusing on specific registry paths and values. This activity is significant because it is a known technique used by adversaries, including malware like RedLine Stealer, to evade detection and potentially deploy additional payloads. If confirmed malicious, this modification could allow attackers to bypass security measures, maintain persistence, and exploit vulnerabilities on the target host.
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="*\\SOFTWARE\\Policies\\Microsoft\\Windows\\WindowsUpdate\\AU\\AUOptions" AND Registry.registry_value_data="0x00000002" 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(lastTime)` | `security_content_ctime(firstTime)` | `windows_modify_registry_auto_update_notif_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` 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: administrators may enable or disable this feature that may cause some false positive.
references:
    - https://learn.microsoft.com/de-de/security-updates/windowsupdateservices/18127499
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 20
          message: A registry modification in Windows auto update notification on $dest$
analytic_story:
    - RedLine Stealer
asset_type: Endpoint
atomic_guid:
    - 12e03af7-79f9-4f95-af48-d3f12f28a260
mitre_attack_id:
    - T1112
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint

Stages and Predicates

Stage 1: tstats

| tstats `security_content_summariesonly` count min(_time) as firstTime max(_time) as lastTime from datamodel=Endpoint.Registry where Registry.registry_path="*\\SOFTWARE\\Policies\\Microsoft\\Windows\\WindowsUpdate\\AU\\AUOptions" AND Registry.registry_value_data="0x00000002" 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

Stage 2: search

| `drop_dm_object_name(Registry)`

Stage 3: search

| `security_content_ctime(lastTime)`

Stage 4: search

| `security_content_ctime(firstTime)`

Stage 5: search

| `windows_modify_registry_auto_update_notif_filter`

Indicators

These rows show field, operator, and value matches.

FieldKindValuesSearch
Registry.registry_patheq
  • "*\\SOFTWARE\\Policies\\Microsoft\\Windows\\WindowsUpdate\\AU\\AUOptions"
field:"registry_path" kind:eq
Registry.registry_value_dataeq
  • "0x00000002" corpus 4 (elastic 2, splunk 2)
field:"Details" kind:eq