Words Double Underlined

[anotheoldgit]

There are certain words on answerbank that are coloured blue and double underlined in blue when I hover over them with the mouse windows pop up with various adverts appertaining to the said word or words on the bottom of the pop ups are the words Free Twit Tube.

There is also a side bar that has appeared on the L/H side with the word RelopiX and giving various related searches, ie Spanish Crossword Puzzles, Sheet Music Song etc, etc.

Anyone help me by telling me what they are and how do I get rid of them?

Firefox and Windows Vista

[factor-fiction]

http://malwaretips.com/blogs/relopix-virus-removal/

[Buenchico]

That's a valid link from F-F but there's possibly quite a lot of overkill there (and it fails to mention that 'resetting' your browser deletes all of your extensions, so that you need to reinstall them all again).

'Step 5' on its own (downloading, installing and running the free version of Malwarebytes Anit-Malware) usually fixes the problem.

[anotheoldgit]

Thanks for your answers, I already have Malwarebytes Anit-Malware Buenchico and I have carried out a full scan but the problem is still there.