Change your passwords just in case, then build it up again. Make sure to secure the site the next time.
first contact your hosting service provider to delete all the mishap that hackers have done and change or reset the password then you can delete all the mishap that hackers have done to your site... hope it helps...
Get help from your host. Once they do some work you'll be able to get back in. Restore your site, but be sure to carefully review the contents of your server. There is a chance they may leave a back door or a virus to get in later. ----------------------<speculation>---------------------------------------- oh...not sure if this helps, and it is speculation...but the owner of this site may be your culprit It's trying to pull a mp3 to play on your hacked page, and it's pulling it from a server that links only to myspace. I would assume that the hacker owns this server, owns that mp3, and has linked it to play. ((Did a "page source" on your hacked page with FireFox)) If that url has nothing to do with your site, I'd block the IP from accessing your server, just in case. ----------------------</speculation>---------------------------------------
I advise against a password change. It just makes the hacker aware your noticed a breakin. Let the hacker think he's successful. If a site is hacked changing passwords does not help much. Hackers are not dumb. Restrict access to the server or website to your own IP address (Ethernet Port, FTP rules, .htaccess etc) and then solve all issues. If done correctly, the hacker can't get in, even with a backdoor. Notify the host just in case and report the IP of the hacker if present. A person who guessed a password can't hardly be called a hacker. I'd say, check what the damages are and then decide what to do. If damages are on the surface only (website/ftp) a passchange may suffice.