If you've not edited any core files upload a fresh copy of the vb files via ftp with overwrite in ascii mode (filezilla is great and free!), then make sure you've done all you can to secure your forum and files, make sure you change all admin and database passwords (don't forget to change the db password in includes/config.php too).

OK, I figured it out. Thanks for all your response. I saw the control panel log and it seems an admin account was hacked into. The same one also created the ads. I have disabled that account and have taken care of it. I have no clue how it was hacked into, but I will do as you suggest and overwrite and probably even upgrade my forum. I have changed all passwords as suggested.

Thank you again!

Don't forget when uploading the nfresh files to leave the images out, they're not usually a problem and chances are that you've already added custom pics to the folder. :)

Will, do, thanks again!