I am fairly sure that one attackers IP is 81.77.51.144 which we have linked back to the UK. Although we got this IP on 10/7/09, so it has probably changed since then. There could be more than one attacker, but I am not entirely sure.

The IP of my servers being attacked is:
118.127.17.234

We know that the person involved owns a hacking website (which I will send you the link to in a PM drunken_fool)

Also some how he is getting access to our console and sometimes spams our server with the URL of his website. We have tried changing the RCON password, but no avail. There must be a major breach in CS:S somewhere that this person is exploiting.