Another Stuxnet Post
So, what did he get wrong? First of all, the Stuxnet worm did not escape into the wild. The analysis of initial infections and propagations by Symantec show that, in fact, that it never was widespread, that it affected computers in closely connected clusters, all of which involved collaborators or companies that had dealings with each other. Secondly, it couldn’t have escaped over the Internet, as Sanger’s account maintains, because it never had that capability built into it: It can only propagate over [a] local-area network, over removable media such as CDs, DVDs, or USB thumb drives. So it was never capable of spreading widely, and in fact the sequence of infections is always connected by a close chain. Another thing that Sanger got wrong … was the notion that the worm escaped when an engineer connected his computer to the PLCs that were controlling the centrifuges and his computer became infected, which then later spread over the Internet. This is also patently impossible because the software that was resident on the PLCs is the payload that directly deals with the centrifuge motors; it does not have the capability of infecting a computer because it doesn’t have any copy of the rest of the Stuxnet system, so that part of the story is simply impossible. In addition, the explanation offered in his book and in his article is that Stuxnet escaped because of an error in the code, with the Americans claiming it was the Israelis’ fault that suddenly allowed it to get onto the Internet because it no longer recognized its environment. Anybody who works in the field knows that this doesn’t quite make sense, but in fact the last version, the last revision to Stuxnet, according to Symantec, had been in March, and it wasn’t discovered until June 17. And in fact the mode of discovery had nothing to do with its being widespread in the wild because in fact it was discovered inside computers in Iran that were being supported by a Belarus antivirus company called VirusBlokAda.
EDITED TO ADD (9/14): Comment from Larry Constantine.