I was looking at Wikipedia earlier and noticed that some entries have certain keywords highlighted in green and are apparently clickable even though they didn't have a link when originally posted. I noticed the same thing here with user Sophie Treadmill. The treadmill part is highlighted in green with 2 lines underneath and also looks to be clickable but of course I'm not taking any chances by doing so. Anyone know whats up with this?I have seen it several times on Wiki but never on SO until now. I also noticed that the word choose where it says choose your icon is the same way.

i'd say you have a virus.

obviously don't click on any of the links.

can you post a Hijack This log, and try to update and run your antivirus

run Malwarebytes (http://download.cnet.com/Malwarebytes-Anti-Malware/3000-8022_4-10804572.html?part=dl-10804572&subj=dl&tag=button)

you could also do an online scan:

http://housecall.trendmicro.com/
http://www.bitdefender.com/scanner/online/free.html (there are others as well)

you'll probably need to identify what that virus is to remove it if Malwarebytes or your antivirus can't remove it.