AMSI Disabled via Registry Modification

Title: AMSI Disabled via Registry Modification
Status: experimental
Description:Detects attempts to disable AMSI (Anti-Malware Scan Interface) by modifying the AmsiEnable registry value. Anti-Malware Scan Interface (AMSI) is a security feature in Windows that allows applications and services to integrate with anti-malware products for enhanced protection against malicious content. Adversaries may attempt to disable AMSI to evade detection by security software, allowing them to execute malicious scripts or code without being scanned.
References:
  -https://mostafayahiax.medium.com/hunting-for-amsi-bypassing-methods-9886dda0bf9d
  -https://docs.microsoft.com/en-us/windows/win32/amsi/antimalware-scan-interface-portal
  -https://www.mdsec.co.uk/2019/02/macros-and-more-with-sharpshooter-v2-0/
Author: Swachchhanda Shrawan Poudel (Nextron Systems)
Date: 2025-12-25
modified:None
Tags:

• -'attack.defense-impairment'
• -'attack.t1685'

Logsource:

• category: registry_set
• product: windows

Detection:
  selection:
    TargetObject|endswith: '\Software\Microsoft\Windows Script\Settings\AmsiEnable'
    Details: 'DWORD (0x00000000)'
  condition:selection
Falsepositives:
  -Unlikely
Level: high