I have called alex and informed him of the exploit. I highly doubt it was targeted. Based on what information I can gather on this "Red_Casper" it seems he searches for exploits in code validation, primarly known bugs based on patches that have been announced, and uses those for his attacks. It almost surely is a SQL exploit, based on his history, and on the fact that this site is FULL of SQL holes, and has been for MONTHS!! !! !
Alex, PLEASE lock down your SQL!! ! Also clean up your code!! !! !
Count yourself lucky this is a non-malicious attack (though I will note that this "Red_Casper" has droped expoits for MSN/passport on sites he owns (possibly on those (s)he exploits as well))
Alex, log dig, determine the actual exploit, and FIX YOUR CODE! Otherwise you'll be lucky if the next time there isn't data loss. Also, patch this site in at least a semi-timely manner, secure the server, etc.
Oh, one final thing, this "Red_Casper" has submitted exploits for IRC bots that run with a php frontend, etc. before, so that is a good spot to start looking.