Ralph Langer has written the definitive analysis of Stuxnet: short, popular version, and long, technical version. Stuxnet is not really one weapon, but two. The vast majority of the attention has been paid to Stuxnet's smaller and simpler attack routine -- the one that changes the speeds of the rotors in a centrifuge, which is used to enrich uranium.
But the second and "forgotten" routine is about an order of magnitude more complex and stealthy. It qualifies as a nightmare for those who understand industrial control system security. And strangely, this more sophisticated attack came first. The simpler, more familiar routine followed only years later -- and was discovered in comparatively short order.

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