PowerShell Script Block Log AMSI Bypass via Reflection or IL Emission
This rule monitors PowerShell Script Block Logging (Event ID 4104) for command patterns indicative of Antimalware Scan Interface (AMSI) or Event Tracing for Windows (ETW) bypass techniques. These include reflective manipulation of AMSI internals (e.g., AmsiUtils, amsiInitFailed), DynamicMethod IL code generation for malicious hooks, and attempts to suppress ETW logging via the PSEtwLog provider.
YARA-L
