Initially, we will explain to you why the antivirus quarantines certain files. The fact is that the essence of the antivirus is to analyse the actions of the program. There are special algorithms by which malware works on your PC. And if you download a normal file, but, according to its algorithm of actions, it will work like a virus (for example, 90% of Crack files), then Webroot, and any other antivirus, will block it and send it to quarantine.