Think I've been hacked please help
 

Hi guys.

I've been having a problem recently with when you click on a link it would send it to forumdir/a/

I figured it was probably a vbseo issues but I've now disabled it and discovered something very alarming.

When I click on section forum on my site it will give a false url


So for example:

I have a forum called 'general discussion' and the url would be /forum/forumdisplay.php?f=10

But once you click on it in the address bar in both firefox and IE it displays the following:

http://www.mydomian.com/forum/wii/

some other examples are forum/original-xbox-games/ forum/ds-dsi/ etc

oh and also forum/a/

my site has NOTHING to do with consoles so I assume I have been hacked??!?!?!

Any help please!!!!!!