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Description

The following analytic identifies a modification in the Windows registry to change the ThrottleDetectionEventsRate of Windows Defender. The ThrottleDetectionEventsRate registry setting in Windows Defender is related to controlling the rate at which detection events are logged or reported by Windows Defender Antivirus. This registry setting determines how frequently Windows Defender logs or reports detection events. Adjusting the ThrottleDetectionEventsRate value can impact the logging frequency of detection events such as malware detections, scanning results, or security-related events recorded by Windows Defender. A higher value might mean that detection events are reported less frequently, potentially reducing the volume of recorded events, while a lower value could increase the reporting frequency, resulting in more frequent logs of detection events.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2024-01-08
  • Author: Teoderick Contreras, Splunk
  • ID: f7da5fca-9261-43de-a4d0-130dad1e4f4d

Annotations

ATT&CK

ATT&CK

ID Technique Tactic
T1562.001 Disable or Modify Tools Defense Evasion
T1562 Impair Defenses 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= "*\\Windows Defender\\NIS\\Consumers\\IPS\\ThrottleDetectionEventsRate" by Registry.registry_key_name Registry.user Registry.registry_path Registry.registry_value_data Registry.action Registry.dest 
| `drop_dm_object_name(Registry)` 
| `security_content_ctime(firstTime)` 
| `security_content_ctime(lastTime)` 
| `windows_impair_defense_change_win_defender_throttle_rate_filter`

Macros

The SPL above uses the following Macros:

:information_source: windows_impair_defense_change_win_defender_throttle_rate_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_value_name
  • Registry.dest
  • Registry.user
  • Registry.registry_path
  • Registry.action

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 Registry node.

Known False Positives

It is unusual to turn this feature off a Windows system since it is a default security control, although it is not rare for some policies to disable it. Although no false positives have been identified, use the provided filter macro to tune the search.

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
49.0 70 70 Windows Defender ThrottleDetectionEventsRate feature was modified 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: 1