Facebook cookies question

My son has a laptop. He also has a facebook account. For the past several weeks has a problem where, after he goes to his facebook page, any link he clicks on directs him back to the homepage set up for his browser. He was initially using Google Chrome, so he thought it might be something wrong with the browser and the cookies and cache. So cleared those and still had the problem. He has installed the following different browsers:
Firefox
Safari
even IE
and the problem still persists. A few google searches brought up few people that have experienced the same problem, but they only recommended solution is to clear the cookies and cache and try again. But that doesn’t work.

He has been able to log into his facebook account from our home computer with no problems.

Any ideas?

Try one more time.

Malware.

He uses MacAfee protection, and it says his PC is clean. I realize that’s not 100% fool proof.