I've disabled the link in your post, as this is a browser virus and we don't want others to get it by visiting that page. Do an Internet search for that website, and you would have found this out yourself. There are various websites describing how to remove it, though all I found have a focus on Windows. Perhaps though this will work: http://techvts.com/remove-cherchi-biz-virus
Do you perhaps have Firefox sync active, or another way to synchronize settings with a browser on Windows? Then your Windows computer will have this virus.
To hopefully easily remove this browser virus, if the above link doesn't help, it is to start with a clean Firefox profile. First step; close all your Firefox windows. Then, open your file manager and press Ctrl+H to show hidden files. Find the .mozilla folder in your home folder and rename it to something else (mozilla-old or something similar). Start Firefox again and test that if you open a new tab it now works as expected. If that works, you may open bookmarks from the menu and select to import bookmarks. Browse to the mozzila-old (or what you renamed the .mozilla folder to) folder, go into firefox, go into <something>.default, and finally into bookmarkbackups. I suggest you load a bookmarks backup from a date you know for sure you didn't have this browser virus. Cookies, passwords and add-ons will have been lost by this action and I suggest you don't recover add-ons. Watch out with installing add-ons, as this browser virus would have been loaded through one of the add-ons you installed yourself as far as I understood it.
I hope you can clear it up this way