Firefox is one of the best browsers for blocking ads and crappy web trackers, and you can make it even better using “nuke-’em-all” browser extensions like uBlock Origin. Now, Ghacks and GitHub users point out that uBlock Origins is even capable of blocking new types of ads, trackers, and website content that browsers like Chrome can’t (or won’t), even with the add-on installed.
This special content uses canonical name (CNAME) records to get through content blockers by telling the browser the content being displayed is important first-party content that needs to be displayed on a website. That’s not the case if you’re using uBlock Origin on Firefox, which is testing out a method for blocking this annoying workaround, too—adding yet another point in the browser’s favour over its competition.
uBlock Origin’s expanded CNAME blocking capabilities for Firefox are in beta right now, but will soon be available in Firefox once the add-on’s version 1.24.1 drops. Whether you grab the beta version now or wait for the next stable update to roll around, users will have to grant a new permission for uBlock Origin to “Access IP address and hostname information.” After that, you’ll need to tweak some of the add-on’s settings to enable advanced ad-blocking:
Type “about:addons” into the Firefox URL bar and press enter to open the extension settings
Click the “…” icon next to uBlock Origins then click “Options”
Check the “I am an advanced user” box then click the gear-shaped icon that appears next to it
In the next window, find “cnameAliasList” from the list, and change the setting’s value to “*”
Click “Apply Changes,” and then close the options. You may need to restart Firefox
After these settings have been changed, uBlock Origins will be able to filter out those pesky ads and trackers using CNAME records.