Iran has charged that an extremely dangerous “foreign-made” computer  worm, “Stuxnet”, has infected tens of thousands of its industrial  computer systems. According to international computer security experts,  the computer worm targets electricity facilities using Siemens control  systems including Iran’s nearly operational Bushehr nuclear power plant  in what is being called the first case of cyber-sabotage of an  industrial system.
The still mutating computer worm is designed to reprogram critical  functions however researchers do not yet know what types of systems are  targeted or how the sabotage is executed. The Islamic Republic News  Agency reports that the virus is not stable and since cleanup efforts  began three new versions of the infection have been spreading.
The computer worm is reported to have first been discovered in June  when researchers found about 45,000 infected computers in various  countries including Indonesia and India. However, leading cyber-security  analysts have concluded that a system in Iran was the focus of the  attack.  The Washington Post quotes a researcher with the security firm  Symantec, “We have never seen anything like this before. It is very  dangerous.”  
The controversial Bushehr nuclear power plant which would generate  weapons usable plutonium as well as electricity was in the final stages  of preparation for operation. Originally of German design and launched  under the Shah, Iran’s first commercial nuclear power plant was being  completed with the aid of Russia after nearly a quarter century of  construction.
The New York Times reports “It is also raising fear of dangerous proliferation. Stuxnet has laid  bare significant vulnerabilities in industrial control systems. The  program is being examined for clues not only by the world’s computer  security companies, but also by intelligence agencies and countless  hackers. 
“Proliferation is a real problem, and no  country is prepared to deal with it,” said Melissa Hathaway, a former  United States national cybersecurity coordinator. The widespread  availability of the attack techniques revealed by the software has set  off alarms among industrial control specialists, she said: “All of these  guys are scared to death. We have about 90 days to fix this before some  hacker begins using it.” 
“The ability of Stuxnet to infiltrate  these systems will 'require a complete reassessment' of security systems  and processes, starting with federal technology standards and nuclear  regulations, said Joe Weiss, a specialist in the security of industrial  control systems who is managing partner at Applied Control Solutions in  Cupertino, Calif.”