14 DAY TRIAL // One day before Mozilla is scheduled to launch a new version of Firefox, the Foundation's security engineers have now detailed the new download protections they have added to Firefox 48.
"Download protections" is not a new feature in Firefox. Mozilla added it to Firefox in version 31 on Windows and version 39 on Mac and Linux.
Until now, the feature has protected users against downloading files from sites marked as malicious in Google's Safe Browsing feature.
Support for PUPs and uncommon downloads
As the Safe Browsing API is constantly evolving, Mozilla has expanded the type of content Firefox is capable of detecting and flagging at runtime.
Starting with Firefox 49, users will see two new types of warnings when downloading files. The first is for potentially unwanted software (also known as potentially unwanted programs - PUPs), and the second is for uncommon downloads.
These warnings are easy to spot. When Firefox has detected a downright dangerous file download, a red warning will appear on top of the download button. When Firefox detects PUPs or uncommon downloads, there will be the same warning, but in yellow.
Uncommon downloads - a new type of threat
Everybody generally knows what PUPs are, a term used to describe software that distributes adware or other hard-to-uninstall programs. On the other hand, the term "unwanted downloads" is something Mozilla coined.
“ The second category, uncommon downloads, covers downloads which may not be malicious or unwanted but that are simply not commonly downloaded. The purpose of this warning is to draw users’ attention to the fact that this may not be the download they think it is. ”
This may include situations where users download a version of Firefox from a website that uses a domain flagged as suspicious (not yet malicious) in Safe Browsing.The Firefox package may be clean and unmodified, but downloading well-known software from this kind of sites is "uncommon" and may be a signal that something is wrong, and that users should stick with more traveled (download) paths.
Below are the settings and warnings you may see when the new download protections will activate.
