Detection rules › Splunk

Disable Windows Behavior Monitoring

Status
production
Severity
medium
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, Steven Dick
Source
github.com/splunk/security_content

The following analytic identifies modifications in the registry to disable Windows Defender's real-time behavior monitoring. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to registry paths associated with Windows Defender settings. This activity is significant because disabling real-time protection is a common tactic used by malware such as RATs, bots, or Trojans to evade detection. If confirmed malicious, this action could allow an attacker to execute code, escalate privileges, or persist in the environment without being detected by antivirus software.

MITRE ATT&CK coverage

TacticTechniques
Defense ImpairmentT1685 Disable or Modify Tools

Event coverage

ProviderEventTitle
SysmonEvent ID 13RegistryEvent (Value Set)

Rule body splunk

name: Disable Windows Behavior Monitoring
id: 79439cae-9200-11eb-a4d3-acde48001122
version: 23
creation_date: '2021-03-31'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk, Steven Dick
status: production
type: TTP
description: The following analytic identifies modifications in the registry to disable Windows Defender's real-time behavior monitoring. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to registry paths associated with Windows Defender settings. This activity is significant because disabling real-time protection is a common tactic used by malware such as RATs, bots, or Trojans to evade detection. If confirmed malicious, this action could allow an attacker to execute code, escalate privileges, or persist in the environment without being detected by antivirus software.
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 Defender\\Real-Time Protection\\DisableBehaviorMonitoring" OR Registry.registry_path= "*\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\\DisableOnAccessProtection" OR Registry.registry_path= "*\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\\DisableScanOnRealtimeEnable" OR Registry.registry_path= "*\\SOFTWARE\\Microsoft\\Windows Defender\\Real-Time Protection\\DisableRealtimeMonitoring" OR Registry.registry_path= "*\\Real-Time Protection\\DisableIntrusionPreventionSystem" OR Registry.registry_path= "*\\Real-Time Protection\\DisableIOAVProtection" OR Registry.registry_path= "*\\Real-Time Protection\\DisableScriptScanning" AND 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)` | where isnotnull(registry_value_data) | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `disable_windows_behavior_monitoring_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: admin or user may choose to disable this windows features.
references:
    - https://tccontre.blogspot.com/2020/01/remcos-rat-evading-windows-defender-av.html
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 ("$dest$") | 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: 7d
      latest_offset: "0"
finding:
    title: Windows Defender real time behavior monitoring disabled on $dest$
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - SolarWinds WHD RCE Post Exploitation
    - Windows Defense Evasion Tactics
    - CISA AA23-347A
    - Revil Ransomware
    - Azorult
    - Windows Registry Abuse
    - Black Basta Ransomware
    - Ransomware
    - RedLine Stealer
    - Cactus Ransomware
    - Scattered Lapsus$ Hunters
    - NetSupport RMM Tool Abuse
    - Storm-0501 Ransomware
    - BlankGrabber Stealer
asset_type: Endpoint
mitre_attack_id:
    - T1685
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562.001/win_app_defender_disabling/windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

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 Defender\\Real-Time Protection\\DisableBehaviorMonitoring" OR Registry.registry_path= "*\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\\DisableOnAccessProtection" OR Registry.registry_path= "*\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\\DisableScanOnRealtimeEnable" OR Registry.registry_path= "*\\SOFTWARE\\Microsoft\\Windows Defender\\Real-Time Protection\\DisableRealtimeMonitoring" OR Registry.registry_path= "*\\Real-Time Protection\\DisableIntrusionPreventionSystem" OR Registry.registry_path= "*\\Real-Time Protection\\DisableIOAVProtection" OR Registry.registry_path= "*\\Real-Time Protection\\DisableScriptScanning" AND 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

Stage 2: search

| `drop_dm_object_name(Registry)`

Stage 3: where

| where isnotnull(registry_value_data)

Stage 4: search

| `security_content_ctime(firstTime)`

Stage 5: search

| `security_content_ctime(lastTime)`

Stage 6: search

| `disable_windows_behavior_monitoring_filter`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Registry.registry_patheq
  • "*\\Real-Time Protection\\DisableIOAVProtection"
  • "*\\Real-Time Protection\\DisableIntrusionPreventionSystem"
  • "*\\Real-Time Protection\\DisableScriptScanning"
  • "*\\SOFTWARE\\Microsoft\\Windows Defender\\Real-Time Protection\\DisableRealtimeMonitoring"
  • "*\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\\DisableBehaviorMonitoring"
  • "*\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\\DisableOnAccessProtection"
  • "*\\SOFTWARE\\Policies\\Microsoft\\Windows Defender\\Real-Time Protection\\DisableScanOnRealtimeEnable"
Registry.registry_value_dataeq
  • "0x00000001" corpus 63 (splunk 54, elastic 9)
registry_value_datais_not_null
  • (no value, null check)