Webmaster Tools "Not Found" for /click.php?

Webmaster Tools is reporting “Not Found” for 134 links. They mostly have a very long URL starting with /click.php?

Any clues anyone as to the source, or the type of code?

Here’s the a full URL example:
http://sandcastle.mobi/click.php?c%3Ed3Gv%5BHOid4St%5BT6uc3Kq’lfzxpset%3ETboe%2CDbtumf’sbol%3E3’f%3Ebtl%3CVT%3C66%3C36%3C35%3C24%3A62355%3Chvz1213%3C85176%3C85176%3Ciptuxbz%3C1%2F13%3A574%3C6431ge4g4243f6e9513794b2391d776b’vsm%3Eiuuq%264B%263G%263G6%3A827%2F234cpvodf%2Fdpn%263Gyus%60ofx%264Gr%264ETboe%263CDbtumf%2637fol%264E%5BpInjXbKqqnQlZ%263C%5Bk7lovTbyk5mHtdcKqrHntTd%264E’gffe%3Eiptuxbz’qsjdf%3E1%2F13%3A574’tbq%3E6431ge4g4243f6e9513794b2391d776b’zbsht%3Ejogp%2Fdpn