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STEVE CHIOTAKIS: Security experts are grappling with what could be a new and serious cyber attack. The Stuxnet computer worm attacks control systems at large sites such as industrial plants and power stations.
From London, here's the BBC's Jon Bithrey.
JON BITHREY: The worm is a piece of malicious programming code. It was first detected in Belarus in June and has since been reported as interfering with software that controls industrial machinery in several countries.
David Emm from the computer security firm Kaspersky believes it's so advanced it could only have been developed with the support of a particular government.
DAVID EMM: The level of sophistication built into this threat, the motivation behind it in terms of disruption, suggests that maybe we're not looking at individual cyber criminals, but there may even be involvement of a particular nation-state in wanting to do this kind of attack.
One respected cyber security expert from Germany has caused a stir by claiming the worm was developed to target a nuclear facility in Iran. Others say there isn't enough evidence to make that claim. But the revelation of the worm has reignited the debate about how technology could be used to attack vital computerized systems.
In London, I'm the BBC's Jon Bithrey for Marketplace.