Windows Impair Defense Disable Win Defender Signature Retirement

name: Windows Impair Defense Disable Win Defender Signature Retirement
id: 7567a72f-bada-489d-aef1-59743fb64a66
version: 12
creation_date: '2024-01-30'
modification_date: '2026-05-13'
author: Teoderick Contreras, Splunk
status: production
type: TTP
description: The following analytic detects modifications to the Windows registry that disable Windows Defender Signature Retirement. It leverages data from the Endpoint.Registry data model, specifically monitoring changes to the DisableSignatureRetirement registry setting. This activity is significant because disabling signature retirement can prevent Windows Defender from removing outdated antivirus signatures, potentially reducing its effectiveness in detecting threats. If confirmed malicious, this action could allow an attacker to evade detection by using older, less relevant signatures, thereby compromising the system's security posture.
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\\NIS\\Consumers\\IPS\\DisableSignatureRetirement" 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_impair_defense_disable_win_defender_signature_retirement_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.
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.
references:
    - https://x.com/malmoeb/status/1742604217989415386?s=20
    - https://github.com/undergroundwires/privacy.sexy
finding:
    title: Windows Defender DisableSignatureRetirement registry is set to enable on $dest$.
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - Windows Defense Evasion Tactics
    - Windows Registry Abuse
    - Scattered Lapsus$ Hunters
asset_type: Endpoint
mitre_attack_id:
    - T1685
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint