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Description

The following analytic detects a suspicious registry modification aimed at disabling Windows Defender notifications. It leverages data from the Endpoint.Registry data model, specifically looking for changes to the registry path "*\SOFTWARE\Policies\Microsoft\Windows Defender Security Center\Notifications\DisableNotifications" with a value of "0x00000001". This activity is significant as it indicates an attempt to evade detection by disabling security alerts, a technique used by adversaries and malware like RedLine Stealer. If confirmed malicious, this could allow attackers to operate undetected, increasing the risk of further compromise and data exfiltration.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2024-05-09
  • Author: Teoderick Contreras, Splunk
  • ID: 8e207707-ad40-4eb3-b865-3a52aec91f26

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1112 Modify Registry Defense Evasion
Kill Chain Phase
  • Exploitation
NIST
  • DE.CM
CIS20
  • CIS 10
CVE 


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| 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 Defender Security Center\\Notifications\\DisableNotifications" AND Registry.registry_value_data="0x00000001" by Registry.dest Registry.user Registry.registry_path Registry.registry_value_data Registry.registry_key_name 
| `drop_dm_object_name(Registry)` 
| `security_content_ctime(lastTime)` 
| `security_content_ctime(firstTime)` 
| `windows_modify_registry_disable_windefender_notifications_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_modify_registry_disable_windefender_notifications_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • Registry.registry_key_name
  • Registry.registry_path
  • Registry.user
  • Registry.dest
  • Registry.registry_value_name
  • Registry.action
  • Registry.registry_value_data

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.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
49.0 70 70 A registry modification to disable Windows Defender notification on $dest$

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.

Reference

Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

source | version: 2