What is happening when my facebook or twitter account redirects to a random blog or myspace page?

J W: What is happening when my facebook or twitter account redirects to a random blog or myspace page?
Sometimes, and always late at night, when I try to log in or out of facebook or twitter and sometimes hulu, my browser redirects to a random blog or myspace page. Is this an indication that there is some sort of malware on my computer? Or that I am being hacked or tracked?

I’m running Mac OSX Leopard from a residential wifi connection at home.

Answers and Views:

Answer by Martial H
Quite possible.

But try to clear your cache or re-install your safari browser, or whatever you’re using.