dstiles - 10:47 pm on Jun 21, 2010 (gmt 0)
That is certainly a bot IP. I wonder if someone has that link on a web site somewhere and yahoo is just following the link. The exploit, obviously, whould be perpetrated from the originating web site not from yahoo following it - there would be no point unless yahoo was actually trying to open you up.
If they made up the url then there is a possible case under the Computer Misuse Act (at least in the UK).
Difficult to tell where it originated, though.