Many "long-term" activations require you to replace a system file (like a .dll ) or use a "loader." These bypass the subscription check but often leave your system vulnerable to the very malware you are trying to prevent.

: Check the official Avast website during holiday sales. They frequently offer up to 70% off multi-device annual plans. How to Properly Activate Avast

: Installers bundled with these keys often contain malware, trojans, or ransomware designed to steal your personal data or lock your system.

If you already bought such a key and it seems to work, run a full scan with or Windows Defender Offline to check for hidden infections.