Trying to download the software for a kobo ereader I got an avast message saying it was dubious software and for the rpotection of my pc it would be downloaded to a sandpit. What and where is a sandpit and how do I access the program downloaded? I don’t believe kobo program would be a problem.
Are you running your browser sandboxed? You need to set the sandbox settings for save downloaded files, otherwise, it could be deleted.
Downloading the file again and checking with www.virustotal.com would also be good.
The AutoSandbox settings are into File Shield ones or, another way, in Additional protection tab of avast!.