I have my preferences set as 'restore previous tabs when opening Firefox' as I want it. To do so, I needed to use the about:config method - I had some adware that made Firefox open as Yahoo. Now, when opening Firefox, the last tab (so the one most to the right) will change to Google - my default search engine. It is also possible that it is the tab that was opened last during the previous session (this always happens to be the last tab). This also happens when opening links in a new tab. The first time it shows Google, the second time it shows the actual webpage that I was linked to. It's also not 'just google' but has a very long URL. I tried to recreate the event, but for some reason linking actually works atm. An URL that was still in my history was https://www.google.be/?gfe_rd=ssl&ei=QBzcVYmUBYG4aNCzv7AN The URLI get when the previous tabs are restored is much shorter: https://www.google.be/?gws_rd=ssl I also get this link when opening google the regular way. I don't remember it always having been like that, so I'm just posting it to be sure.