Sigma rule: AMSI Disabled via Registry Modification

Rule

Title

AMSI Disabled via Registry Modification

Status

experimental

Level

high

Author

Swachchhanda Shrawan Poudel (Nextron Systems)

Date

2025-12-25

File

rules/windows/registry/registry_set/registry_set_amsi_disable.yml

Commit

ccbb0369507f796db0b0ae6854c8a2be471b9d84

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.

Log source

product

windows

category

registry_set

Detection

selection:
    TargetObject|endswith: '\Software\Microsoft\Windows Script\Settings\AmsiEnable'
    Details: 'DWORD (0x00000000)'
condition: selection

False positives (as the rule lists them)

• Unlikely

Tags

• attack.defense-impairment
• attack.t1685

MITRE ATT&CK ids this rule names

• T1685

Related rules

• 7dbbcac2-57a0-45ac-b306-ff30a8bd2981 (similar)

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/

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/windows/registry/registry_set/registry_set_amsi_disable.yml