Stuxnet, the First Malware to Spy on and Subvert Industrial Systems

In June 2010 the Stuxnet computer worm, the first malware that spied on and subverted industrial systems, was discovered.  Stuxnet was also the first malware to include a programmable logic controller (PLC) rootkit. 

"The worm initially spreads indiscriminately, but includes a highly specialized malware payload that is designed to target only Siemens supervisory control and data acquisition (SCADA) systems that are configured to control and monitor specific industrial processes. Stuxnet infects PLCs by subverting the Step-7 software application that is used to reprogram these devices.

"Different variants of Stuxnet targeted five Iranian organizations, with the probable target widely suspected to be uranium enrichment infrastructure in Iran; Symantec noted in August 2010 that 60% of the infected computers worldwide were in Iran. Siemens stated on 29 November that the worm has not caused any damage to its customers, but the Iran nuclear program, which uses embargoed Siemens equipment procured secretly, has been damaged by Stuxnet. Kaspersky Lab concluded that the sophisticated attack could only have been conducted "with nation-state support". This was further supported by the F-Secure's chief researcher Mikko Hyppönen who commented in a Stuxnet FAQ, 'That's what it would look like, yes'. It has been speculated that Israel and the United States may have been involved. . . .

"Experts believe that Stuxnet required the largest and costliest development effort in malware history. Its many capabilities would have required a team of people to program, in-depth knowledge of industrial processes, and an interest in attacking industrial infrastructure. Eric Byres, who has years of experience maintaining and troubleshooting Siemens systems, told Wired that writing the code would have taken many man-months, if not years. Symantec estimates that the group developing Stuxnet would have consisted of anywhere from five to thirty people, and would have taken six months to prepare. The Guardian, the BBC and The New York Times all claimed that (unnamed) experts studying Stuxnet believe the complexity of the code indicates that only a nation-state would have the capabilities to produce it. The self-destruct and other safeguards within the code imply that a Western government was responsible, with lawyers evaluating the worm's ramifications. Software security expert Bruce Schneier condemned the 2010 news coverage of Stuxnet as hype, however, stating that it was almost entirely based on speculation. But after subsequent research, Schneier stated in 2012 that 'we can now conclusively link Stuxnet to the centrifuge structure at the Natanz nuclear enrichment lab in Iran' " (Wikipedia article on Stuxnet, accessed 05-30-2012).