September 27, 2010, 1:18 PM — Although some computers at Iran's Bushehr nuclear reactor were infected by the Stuxnet worm, none of the facility's crucial control systems were affected, Iranian officials claimed Sunday.
The news followed Saturday's admission by Iran that Stuxnet had infected at least 30,000 computers in the country. The worm, which researchers have dubbed the most sophisticated malware ever , targets Windows PCs that manage large-scale industrial-control systems in manufacturing and utility companies.
Those control systems, called SCADA, for "supervisory control and data acquisition," manage and monitor machinery in power plants, factories, pipelines and military installations.
"The studies show that few PCs of Bushehr nuclear power plant workers are infected with the virus," Mahmoud Jafari, the facility's project manager, told Iran's state-run Islamic Republic News Agency on Sunday.
Jafari denied that the worm had caused major damage to SCADA systems, or that Stuxnet had delayed the reactor's completion.
Bushehr is slated to go online in the next few months. In late August, workers began loading the reactor with nuclear fuel.
Stuxnet has attracted as much attention for its presumed target as for its technical expertise. Shortly after a Belarus antivirus firm reported finding the worm, U.S.-based security company Symantec noted that Iran was hit hardest , with approximately 60% of all infections traced to that country's computers.
Since then, experts have amassed evidence that Stuxnet has been attacking industrial control systems since at least January 2010, while others have speculated that the worm was developed by a state-sponsored team of programmers and designed to cripple the Bushehr reactor .
The reactor, located in southwestern Iran near the Persian Gulf, has been one of the flash points of tension between Iran and the West, including the U.S., which believes that spent fuel from the reactor could be reprocessed elsewhere in the country to produce weapons-grade plutonium for use in nuclear warheads.