Complete protection against usb viruses.

Anything that tries to run from usb will invoke auto sandbox? Yes my autorun is disabled. Can i run the whole usb in a sandbox

The avast file system shield (FSS) will scan any files that are activated/run from the USB as a resident antivirus should do. This may or may not result in the the autosandbox being activated, depends on what the FSS thinks.

No you can’t run the whole USB sandboxed.

Only the Pro/Paid versions of avast have a full selective sandbox function, but that doesn’t sandbox areas as such, you select the programs, browsers, etc. that will be sandboxed. So you can’t select an area such as a USB which may have multiple applications.