Windows AMSI Provider Registry Key Deletion (HKLM\Software\Microsoft\AMSI)
Alerts on deletion of AMSI provider registry key entries under HKLM\Software\Microsoft\AMSI, potentially indicating AMSI inspection impairment.
- Product
- windows
- Category
- registry_delete
- Author
- frack113 (SigmaHQ), DRL 1.1
- Published
- 2021-06-07
- Updated
- 2026-07-30
ATT&CK techniques
Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact
What it detects
This rule flags deletion of specific AMSI provider registry key entries under HKLM\Software\Microsoft\AMSI. Removing these entries can be used by an attacker to impair or disable AMSI-based inspection. The detection relies on Windows registry delete telemetry for the matching TargetObject identifiers, with exclusions for common Windows Defender platform activity associated with MsMpEng.exe.
Reporting behind it
- github.comhttps://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1562.001/T1562.001.md
- seclists.orghttps://seclists.org/fulldisclosure/2020/Mar/45
- github.comhttps://github.com/SigmaHQ/sigma/blob/master/rules/windows/registry/registry_delete/registry_delete_removal_amsi_registry_key.yml
Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.
title: Windows AMSI Provider Registry Key Deletion (HKLM\Software\Microsoft\AMSI)
id: b5db911d-3827-4793-8d95-35a4af0c4f2e
status: test
description: This rule flags deletion of specific AMSI provider registry key entries under HKLM\Software\Microsoft\AMSI. Removing these entries can be used by an attacker to impair or disable AMSI-based inspection. The detection relies on Windows registry delete telemetry for the matching TargetObject identifiers, with exclusions for common Windows Defender platform activity associated with MsMpEng.exe.
references:
- https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1562.001/T1562.001.md
- https://seclists.org/fulldisclosure/2020/Mar/45
- https://github.com/SigmaHQ/sigma/blob/master/rules/windows/registry/registry_delete/registry_delete_removal_amsi_registry_key.yml
author: frack113, Huntrule Team
date: 2021-06-07
modified: 2025-10-07
tags:
- attack.defense-impairment
- attack.t1685
logsource:
product: windows
category: registry_delete
detection:
selection:
TargetObject|endswith:
- "{2781761E-28E0-4109-99FE-B9D127C57AFE}"
- "{A7C452EF-8E9F-42EB-9F2B-245613CA0DC9}"
filter_main_defender:
Image|startswith:
- C:\ProgramData\Microsoft\Windows Defender\Platform\
- C:\Program Files\Windows Defender\
- C:\Program Files (x86)\Windows Defender\
Image|endswith: \MsMpEng.exe
condition: selection and not 1 of filter_main_*
falsepositives:
- Unlikely
level: high
regression_tests_path: regression_data/rules/windows/registry/registry_delete/registry_delete_removal_amsi_registry_key/info.yml
simulation:
- type: atomic-red-team
name: AMSI Bypass - Remove AMSI Provider Reg Key
technique: T1562.001
atomic_guid: 13f09b91-c953-438e-845b-b585e51cac9b
license: DRL-1.1
related:
- id: 41d1058a-aea7-4952-9293-29eaaf516465
type: derived