AMSI Bypass via amsiInitFailed Reflection in PowerShell (UAC-0226 / T1562.001)

Ibrahim Saud@tektrix

•updated Jun 29, 2026•0•0•0

This rule detects common PowerShell command-line arguments and patterns used by attackers to bypass or disable Antimalware Scan Interface (AMSI) in memory. Attackers often attempt to modify non-public, static members of the AmsiUtils class to force AMSI initialization failure, allowing for the execution of malicious scripts without detection.