The IP is out of Ukraine.. theres a big suprise.. I'd say you need a full scan on that box.
Inhoster hosting company AKA.. ESTDOMAINS, INC.
http://www.ripe.net/whois?form_type=..._search=Search
Those guys are pretty smart or getting smarter on their cheating and are pretty big time cheating operation. I'm sure they have blocked your IP address and any one whom has logged into your machine from seeing the exploit.