Most Popular Detection 2026: AMSI Bypass Attempt Detection
Detects attempts to bypass the Antimalware Scan Interface (AMSI) in PowerShell. The rule looks for command-line arguments referencing AMSI-related memory structures, methods, and DLLs such as AmsiUtils, AmsiScanBuffer, AmsiInitFailed, and amsi.dll. Bypassing AMSI is a common technique used by attackers to execute malicious scripts and deploy fileless payloads, such as Cobalt Strike or Sliver, while avoiding detection by endpoint security solutions.
YARA-L
