If I recall correct, this was a vulnerability/exploit/Injection in VBulletin. I haven't seen this in a while but is related on people not been loogged in and login redirection. This was only affecting VB CMS edition.
I have on bookmarks thebuddyforum.com/forum.php because everytime the home page says I am not login when I am actually logged in.
Do we have any information on what's happening or any possible cure coming soon?