Detection rules › Splunk
Windows Modify Registry Suppress Win Defender Notif
The following analytic detects modifications in the Windows registry to suppress Windows Defender notifications. It leverages data from the Endpoint.Registry datamodel, specifically targeting changes to the "Notification_Suppress" registry value. This activity is significant because adversaries, including those deploying Azorult malware, use this technique to bypass Windows Defender and disable critical notifications. If confirmed malicious, this behavior could allow attackers to evade detection, maintain persistence, and execute further malicious activities without alerting the user or security tools.
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Persistence | T1112 Modify Registry |
| Defense Impairment | T1112 Modify Registry |
Event coverage
| Provider | Event | Title |
|---|---|---|
| Sysmon | Event ID 13 | RegistryEvent (Value Set) |
Rule body splunk
name: Windows Modify Registry Suppress Win Defender Notif
id: e3b42daf-fff4-429d-bec8-2a199468cea9
version: 11
creation_date: '2022-06-22'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: Anomaly
description: The following analytic detects modifications in the Windows registry to suppress Windows Defender notifications. It leverages data from the Endpoint.Registry datamodel, specifically targeting changes to the "Notification_Suppress" registry value. This activity is significant because adversaries, including those deploying Azorult malware, use this technique to bypass Windows Defender and disable critical notifications. If confirmed malicious, this behavior could allow attackers to evade detection, maintain persistence, and execute further malicious activities without alerting the user or security tools.
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= "*\\Windows Defender\\UX Configuration\\Notification_Suppress*" 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)` | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `windows_modify_registry_suppress_win_defender_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 `Registry` node. Also make sure that this registry was included in your config files ex. sysmon config to be monitored.
known_false_positives: administrators may enable or disable this feature that may cause some false positive.
references:
- https://docs.microsoft.com/en-us/windows-hardware/customize/desktop/unattend/microsoft-windows-remoteassistance-exe-fallowtogethelp
- https://app.any.run/tasks/a6f2ffe2-e6e2-4396-ae2e-04ea0143f2d8/
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"
intermediate_findings:
entities:
- field: dest
type: system
score: 20
message: the registry for suppresing windows fdefender notification settings was modified to disabled on $dest$
analytic_story:
- Azorult
- CISA AA23-347A
asset_type: Endpoint
mitre_attack_id:
- T1112
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/malware/azorult/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= "*\\Windows Defender\\UX Configuration\\Notification_Suppress*" 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: search
| `security_content_ctime(firstTime)`
Stage 4: search
| `security_content_ctime(lastTime)`
Stage 5: search
| `windows_modify_registry_suppress_win_defender_notif_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.
| Field | Kind | Values |
|---|---|---|
Registry.registry_path | eq |
|
Registry.registry_value_data | eq |
|