This was part of the NG system of virtualisation on the users system. Many found that their system was either not up to the task of running NG or slowed the system down.

Avast has now implemented a system that is avast cloud based, CyberCapture, so the scanning/virtualisation is done in the cloud, with little impact or no on the users system. See https://blog.avast.com/cybercapture-protection-against-zero-second-attacks for more information.