Security Experts:

Connect with us

Hi, what are you looking for?


Endpoint Security

Firefox Adds Improved Download Protection

Mozilla on Monday announced that download protection in Firefox 48 has ben expanded to include potentially unwanted software and uncommon downloads.

Mozilla on Monday announced that download protection in Firefox 48 has ben expanded to include potentially unwanted software and uncommon downloads.

Mozilla introduced download protection two years ago in Firefox 31 on Windows, then added it to Mac and Linux releases in Firefox 39. Designed to warn users when they were about to download harmful files, the feature is powered by the Google Safe Browsing API, and is meant to complement the already available warnings on potentially malicious websites.

Now, because Google has expanded the Safe Browsing service to cover more types of malicious files, Firefox is expanding its security capabilities too, Francois Marier, Security and Privacy Engineer, Mozilla, explains in a blog post.

Starting in Firefox 48, users will be alerted when they attempt to download an application that could make unexpected changes to the computer, otherwise known as potentially unwanted program (PUP) or application (PUA). Such applications could collect user information, display ads, install toolbars or other applications with questionable intentions, or use various techniques to make them difficult to uninstall. 

Uncommon downloads, on the other hand, are downloads that might not be malicious nor would they fall in the unwanted category, but which aren’t usually downloaded. According to Mozilla, Firefox will display a warning on this type of downloads so that users are alerted on the fact that they might not be downloading the file they believe they are.

For example, when a user attempts to download a popular application and the warning appears, chances are they might have been tricked into downloading a malicious file instead, possibly from a phishing site that hasn’t been yet identified as dangerous by Google’s Safe Browsing service. It also means that the user should re-check the downloaded package before opening it.

Following these improvements, users will also notice a series of interface changes in Firefox, meant to help them better notice and understand the aforementioned warnings. A confirmation dialog will popup, to help users understand the risks involved. Furthermore, users will also have the option to remove the offending files directly from the browser.

Firefox 48 will also provide users with increased control over download and browsing protection. Users can block all dangerous and deceptive content, which will warn them when visiting pages that contain malware or deceptive content, but can also opt to block only dangerous downloads, which are usually malicious executable files, or only to be warned about unwanted and uncommon software.

“While we believe that the vast majority of our users will prefer to keep all of the protections that Safe Browsing offers, we understand that some users may choose to disable parts of the Safe Browsing service based on the privacy guarantees they offer. Our new options aim to give concerned users the necessary level of control and to enable them to retain as much of the Safe Browsing service as they are comfortable with,” Marier says.

Related: Firefox Blocks Flash Content to Improve Security

Related: Microsoft Unveils Protection Against Potentially Unwanted Applications

Related: Google Improves Safe Browsing for Network Admins

Written By

Click to comment

Expert Insights

Related Content

Malware & Threats

Microsoft plans to improve the protection of Office users by blocking XLL add-ins from the internet.


CISA, NSA, and MS-ISAC issued an alert on the malicious use of RMM software to steal money from bank accounts.


Chinese threat actor DragonSpark has been using the SparkRAT open source backdoor in attacks targeting East Asian organizations.


A recently disclosed vBulletin vulnerability, which had a zero-day status for roughly two days last week, was exploited in a hacker attack targeting the...

Application Security

Electric car maker Tesla is using the annual Pwn2Own hacker contest to incentivize security researchers to showcase complex exploit chains that can lead to...

Malware & Threats

Cybercrime in 2017 was a tumultuous year "full of twists and turns", with new (but old) infection methods, a major return to social engineering,...

Malware & Threats

Norway‎-based DNV said a ransomware attack on its ship management software impacted 1,000 vessels.


Security researchers with Juniper Networks’ Threat Labs warn of a new Python-based backdoor targeting VMware ESXi virtualization servers.