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Description

This analytic is to detect a suspicious modification of registry to disable windows defender feature. This technique is to bypassed or evade detection from Windows Defender AV product specially the spynet reporting for its telemetry.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud
  • Datamodel: Endpoint
  • Last Updated: 2022-01-26
  • Author: Teoderick Contreras, Splunk
  • ID: 898debf4-3021-11ec-ba7c-acde48001122

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
CIS20
CVE
1
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| tstats `security_content_summariesonly` count from datamodel=Endpoint.Registry where Registry.registry_path = "*\\Microsoft\\Windows Defender\\SpyNet*" Registry.registry_value_name = SpynetReporting Registry.registry_value_data = 0x00000000 by _time span=1h Registry.dest Registry.user Registry.registry_path Registry.registry_value_name Registry.registry_value_data Registry.process_guid 
| `drop_dm_object_name(Registry)` 
|rename process_guid as proc_guid 
|join proc_guid, _time [
| tstats `security_content_summariesonly` count FROM datamodel=Endpoint.Processes by _time span=1h Processes.process_id Processes.process_name Processes.process Processes.dest Processes.parent_process_name Processes.parent_process Processes.process_guid 
| `drop_dm_object_name(Processes)` 
|rename process_guid as proc_guid 
| fields _time dest user parent_process_name parent_process process_name process_path process proc_guid registry_path registry_value_name registry_value_data] 
| table _time dest user parent_process_name parent_process process_name process_path process proc_guid registry_path registry_value_name registry_value_data 
| `disable_defender_spynet_reporting_filter`

Macros

The SPL above uses the following Macros:

:information_source: disable_defender_spynet_reporting_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.dest
  • Registry.user
  • Registry.registry_value_name
  • Registry.registry_key_name
  • Registry.registry_path
  • Registry.registry_value_data

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 6.0.4 of the Sysmon TA.

Known False Positives

admin or user may choose to disable windows defender product

Associated Analytic Story

RBA

Risk Score Impact Confidence Message
49.0 70 70 modified/added/deleted registry entry $registry_path$ in $dest$

: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