AMSI Bypass via DynamicMethod IL Emission Targeting s_amsiInitFailed
This rule detects PowerShell script blocks attempting to bypass the Antimalware Scan Interface (AMSI) using .NET reflection techniques. It specifically looks for patterns involving the manipulation of internal AMSI fields, such as 'AmsiUtils', 's_amsiInitFailed', and 'DynamicMethod', which are common indicators of malicious attempts to disable or evade script content analysis in memory.
Cortex XDR

