abuse from bots with no user agent string

[Brewster]

Anyone got any experience with dealing with aggressive bots with no user agent string?

I run a wordpress blog that has had an unknown robot use up 9.03 MB of bandwidth in 46,971 hits. I'm guessing that a bot that doesnt have a user agent string isn't likely to check for a robots.txt, so is there a way of detecting and blocking this with either csf or mod security?

Any help would be much appreciated.

Thanks,
JOe

[Sergio]

Mod_Security will do the job, have you tried to use ASL rules?

Sergio