Windows DisableAntiSpyware Registry

SPLUNK detection rule by Rod Soto, Jose Hernandez, Michael Haag, Splunk · Apache-2.0

The following analytic detects the modification of the Windows Registry key "DisableAntiSpyware" being set to disable. This detection leverages data from the Endpoint.Registry datamodel, specifically looking for the registry value name "DisableAntiSpyware" with a value of "0x00000001". This activity is significant as it is commonly associated with Ryuk ransomware infections, indicating potential malicious intent to disable Windows Defender. If confirmed malicious, this action could allow attackers to disable critical security defenses, facilitating further malicious activities such as data encryption, exfiltration, or additional system compromise.

name: Windows DisableAntiSpyware Registry
id: 23150a40-9301-4195-b802-5bb4f43067fb
version: 13
creation_date: '2020-11-06'
modification_date: '2026-05-13'
author: Rod Soto, Jose Hernandez, Michael Haag, Splunk
status: production
type: TTP
description: The following analytic detects the modification of the Windows Registry key "DisableAntiSpyware" being set to disable. This detection leverages data from the Endpoint.Registry datamodel, specifically looking for the registry value name "DisableAntiSpyware" with a value of "0x00000001". This activity is significant as it is commonly associated with Ryuk ransomware infections, indicating potential malicious intent to disable Windows Defender. If confirmed malicious, this action could allow attackers to disable critical security defenses, facilitating further malicious activities such as data encryption, exfiltration, or additional system compromise.
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_value_name="DisableAntiSpyware" 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)` | `security_content_ctime(lastTime)` | `security_content_ctime(firstTime)` | `windows_disableantispyware_registry_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://blog.malwarebytes.com/malwarebytes-news/2021/02/lazyscripter-from-empire-to-double-rat/
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 DisableAntiSpyware registry key set to 'disabled' on $dest$
    entity:
        field: dest
        type: system
        score: 50
analytic_story:
    - SolarWinds WHD RCE Post Exploitation
    - Azorult
    - Ryuk Ransomware
    - Windows Registry Abuse
    - RedLine Stealer
    - CISA AA22-264A
    - Windows Defense Evasion Tactics
    - CISA AA23-347A
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/atomic_red_team/windows-sysmon.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

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1e52a140-39c0-4a1c-93ef-b91aa3481ae9

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