Mozilla has announced that the new version 31.0 of Firefox, released earlier this week,
will check individual file downloads against Google's Safe Browsing reputation service to determine if they are known malware.
Firefox has checked web site URLs against
Google's Safe Browsing service since version 2.0. Originally, that service checked only to see if sites were known phishing sites; later on, a list of sites known to serve malware was added to the service. When you encounter such a site, Firefox raises an interstitial warning:
