How can we block RSBot?

[dozy]

A student was asking for more storage space and upon looking at the contents of his documents I came across a folder called ".jagex_cache_32" which was over 110Mb in size. I also found an executable .jar file called "RSBot-228.jar" of around 1Mb. Doing some investigation seems like the RSBot comes from the following website www.powerbot.org and is to do with cheating on the Runescape game.

I have checked our SchoolGuardian logs and its not mentioning anything about it so I can only assume that the program/game is bypassing our filters by going straight to our default gateway.

Does anyone have any ideas on how to block this site/game? I am thinking along the lines of a group policy that prevents any .jar file from running but am wondering what that is going to break!

Any ideas much appreciated,
Thanks,
Chris.

[sonofsanta]

FSRM? Posted about it just t'other day - would stop any JAR files being saved in whichever folders you define, and trigger an email. Then just do a search, cut and paste into a folder elsewhere. If nothing is broken a month after that, delete that folder. Sit back and enjoy the complaints from students.