Mozilla Hardens Firefox Security By Blocking Cryptominers And Sneaky Browser Fingerprinting

At a cursory glance, it may seem like cryptocurrency mining is firmly in the rear view mirror, along with all of the unwanted side effects (GPU shortages, browser hijacking, and so forth), but not so fast. Bitcoin and other virtual currencies have seen a sharp rise in recent weeks. Does that mean we have to worry about sneaky web code using our browsers to mine cryptocurrencies? That remains to be seen, though to prevent that sort of thing, Mozilla is making some changes to Firefox.

Mozilla stated in a blog post that it has added a feature to block fingerprinting and cryptomining in Firefox Nightly, as an option for users to turn on. Firefox Nightly is a pre-release version of Firefox that gets updated daily with new code and features. Some of those features make their way through more polished builds—Aurora and Beta—and into a general release.

What exactly is fingerprinting? These are scripts that get embedded into webpages, for the purpose of harvesting snapshots of a computer's configuration. That data can then be used to compile a digital fingerprint of your PC, allowing it to be tracked across the web, even after you have cleared away your browser's tracking cookies.

Mozilla is working to block those kinds of scripts, as well as cryptomining scripts that tap into your PC's resources, through the browser, to mine cryptocurrency for someone else's benefit.

"To combat these threats, we are pleased to announce new protections against fingerprinters and cryptominers ...In the coming months, we will start testing these protections with small groups of users and will continue to work with Disconnect to improve and expand the set of domains blocked by Firefox. We plan to enable these protections by default for all Firefox users in a future release," Mozilla said.

In addition to being part of Firefox Nightly, Mozilla says the new protections can also be turned on in the Beta build. To find them, open up the main menu in Firefox, choose Preference, and click on Privacy and Security on the left-hand side. Under the Content Blocking section, click on Custom, and then check the boxes for Cryptominers and Fingerprinters.