Dual warhead stuxnet

http://www.nytimes.com/2010/11/20/world/middleeast/20stuxnet.html?_r=1&ref=technology

German software engineer who in September was the first to report that a computer worm was apparently designed to sabotage targets in Iran said Friday that the program contained two separate “digital warheads.”… malicious program, known as Stuxnet, is designed to disable both Iranian centrifuges used to enrich uranium and steam turbines at the Bushehr nuclear power plant…link between the worm and an Iranian target was first made at an industrial systems cybersecurity conference in the Washington area on Sept. 20 by Mr. Langner…In a statement Friday on his Web site, he described two different attack modules that are designed to run on different industrial controllers made by Siemens, the German industrial equipment maker. “It appears that warhead one and warhead two were deployed in combination as an all-out cyberstrike against the Iranian nuclear program,”… Mr. Langner said, however, that he had found enough evidence within the programs to pinpoint the intended targets. He described his research process as being akin to being at a crime scene and examining a weapon but lacking a body…second code module — aimed at the nuclear power plant — was written with remarkable sophistication, he said. The worm moves from personal computers to Siemens computers that control industrial processes. It then inserts fake data, fooling the computers into thinking that the system is running normally while the sabotage of the frequency converters is taking place. “It is obvious that several years of preparation went into the design of this attack,”… concerned that computer security organizations were not adequately conveying the potential for serious industrial sabotage that Stuxnet foretells…