Modification of AmsiEnable Registry Key

Last updated 5 months ago on 2025-03-20
Created 4 years ago on 2021-06-01

About

Identifies modifications of the AmsiEnable registry key to 0, which disables the Antimalware Scan Interface (AMSI). An adversary can modify this key to disable AMSI protections.
Tags
Domain: EndpointOS: WindowsUse Case: Threat DetectionTactic: Defense EvasionData Source: Elastic EndgameData Source: Elastic DefendData Source: SysmonData Source: Microsoft Defender for EndpointData Source: SentinelOneLanguage: eql
Severity
high
Risk Score
73
MITRE ATT&CK™

Defense Evasion (TA0005)(opens in a new tab or window)

License
Elastic License v2(opens in a new tab or window)

Definition

Rule Type
Event Correlation Rule
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
winlogbeat-*logs-endpoint.events.registry-*logs-windows.sysmon_operational-*endgame-*logs-m365_defender.event-*logs-sentinel_one_cloud_funnel.*
Related Integrations

endpoint(opens in a new tab or window)

windows(opens in a new tab or window)

m365_defender(opens in a new tab or window)

sentinel_one_cloud_funnel(opens in a new tab or window)

Query
registry where host.os.type == "windows" and event.type == "change" and
  registry.value : "AmsiEnable" and registry.data.strings: ("0", "0x00000000")

  /*
    Full registry key path omitted due to data source variations:
    HKEY_USERS\\*\\Software\\Microsoft\\Windows Script\\Settings\\AmsiEnable"
  */

Install detection rules in Elastic Security

Detect Modification of AmsiEnable Registry Key in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).