For those so inclined, here's some surprising information on Stuxnet, and a recent variant, from F-Secure--
Q: Who could have written Stuxnet?
A: Looking at the financial and R&D investment required and combining this with the fact that there's no obvious money-making mechanism within Stuxnet, that leaves only two possibilities: a terror group or a nation-state. And we don't believe any terror group would have this kind of resources.
Q: So was Stuxnet written by a government?
A: That's what it would look like, yes.
Q: How could governments get something so complex right?
A: Trick question. Nice. Next question.
Q: Was it Israel?
A: We don't know.
Q: Was it Egypt? Saudi Arabia? USA?
A: We don't know.
Q: Was the target Iran?
A: We don't know.
How does Stuxnet know it has already infected a machine?
A: It sets a Registry key with a value "19790509" as an infection marker.
Q: What's the significance of "19790509"?
A: It's a date. 9th of May, 1979.
Q: What happened on 9th of May, 1979?
A: Maybe it's the birthday of the author? Then again, on that date a Jewish-Iranian businessman called Habib Elghanian was executed in Iran. He was accused to be spying for Israel.
Q: Oh.
A: Yeah.
Q: Did Stuxnet sink Deepwater Horizon and cause the Mexican oil spill?
A: No, we do not think so. Although it does seem Deepwater Horizon indeed did have some Siemens PLC systems on it.
Q: Is it true that the US Senate held hearings on Stuxnet?
A: Yes, in November.
Full Stuxnet Q&A from F-SecureStuxnet could be why Germany suddenly shut down all of its nuke plants in March of last year.....
German Shut DownAs reported by F-Secure in October of last year, seems that there is a Stuxnet variant by the name of Duqu that was created by the authors of Stuxnet.
DuquThe extrapolations of all this are rather sobering, as most industrial and municipal entities use Siemens PLC's in their respective processes....