Who exploded the Stuxnet bomb in Iran?

So it looks like malware has got serious with the arrival of Stuxnet which, instead of targeting financial gain, appears to have been aimed directly at real-world, critical infrastructure. There are even those who believe that Stuxnet is less malware and more weapon, with the BBC reporting security experts suggesting that the worm was sponsored by a nation state and designed specifically to target Iran’s nuclear power plant. Indeed, since it first appeared in June Stuxnet would seem to have been most infectious within Iran than anywhere else. Research from Symantec shows close on 60 percent of all the Stuxnet infections have been located within Iran.