incrediBILL - 12:57 am on Jul 6, 2010 (gmt 0)

Yikes!

I haven't been paying attention but this one is nasty

I've seen UAs of "Casper Bot Search", "rk q kangen" and "MaMa CaSpEr"

They're all trying to find ways to upload files to my site such as:
"somepage.html?path=http://www.example.com/www/data/casper/Ckrid1.txt?"

I would block anything with "/casper/" in the query string as an added measure of protection.