Hacked Sites

I have a site hacked

69paintball.com

When I google it I get this description..

Paintball Guns | Paintball Gear
Copyright © 2007 Looking for Paintball Guns? Mycelex-g Dosage Mycelex-g No Prescription Mycelex-g No Rr Mycelex-g On Line Mycelex-g Online Mycelex-g Online …
http://www.69paintball.com/ – 58k – Cached – Similar pages

Clicking on the link to my site leads me to a blank page at this url..

http://sattan.org/feed/search.php?q=69paintball.com

I upgraded to 2.7, but know that its still not safe. I placed ad links on it and they’re showing prescription drug links.

How do I find whats wrong? or do I have to reinstall?