In the chrome store Comodo has been offering a extension called Comodo Cloud antivirus, link After you install the extension Comodo asks you to install the portable sandbox also. It uses the reputation services of Comodo and seems to - allows known good to run - runs unknown in sandbox - deletes known malware It is an interesting concept, raising questions like: what is the default behaviour when Comodo's reputation service has not responded (my bet would be treat it like unknown)? Anyone experience with it?