There's a longish article in today's NYT that's definitely worth reading if you're at all interested in this case.
Key takeaways: confirmation that it was an Israeli-led operation, confirmation that it was a joint Israeli-American effort with cooperation from Siemens, increased confidence that the attack was quite successful. Some excerpts:
Though American and Israeli officials refuse to talk publicly about what goes on at Dimona ["complex in the Negev desert is famous as the heavily guarded heart of Israel’s never-acknowledged nuclear arms program"], the operations there, as well as related efforts in the United States, are among the newest and strongest clues suggesting that the virus was designed as an American-Israeli project to sabotage the Iranian program.
In recent days, the retiring chief of Israel’s Mossad intelligence agency, Meir Dagan, and Secretary of State Hillary Rodham Clinton separately announced that they believed Iran’s efforts had been set back by several years. Mrs. Clinton cited American-led sanctions, which have hurt Iran’s ability to buy components and do business around the world.
The gruff Mr. Dagan, whose organization has been accused by Iran of being behind the deaths of several Iranian scientists, told the Israeli Knesset in recent days that Iran had run into technological difficulties that could delay a bomb until 2015. That represented a sharp reversal from Israel’s long-held argument that Iran was on the cusp of success.
The biggest single factor in putting time on the nuclear clock appears to be Stuxnet, the most sophisticated cyberweapon ever deployed.
In interviews over the past three months in the United States and Europe, experts who have picked apart the computer worm describe it as far more complex — and ingenious — than anything they had imagined when it began circulating around the world, unexplained, in mid-2009.
In early 2008 the German company Siemens cooperated with one of the United States’ premier national laboratories, in Idaho, to identify the vulnerabilities of computer controllers that the company sells to operate industrial machinery around the world — and that American intelligence agencies have identified as key equipment in Iran’s enrichment facilities.
Officially, neither American nor Israeli officials will even utter the name of the malicious computer program, much less describe any role in designing it.
But Israeli officials grin widely when asked about its effects. Mr. Obama’s chief strategist for combating weapons of mass destruction, Gary Samore, sidestepped a Stuxnet question at a recent conference about Iran, but added with a smile: “I’m glad to hear they are having troubles with their centrifuge machines, and the U.S. and its allies are doing everything we can to make it more complicated.”
In recent days, American officials who spoke on the condition of anonymity have said in interviews that they believe Iran’s setbacks have been underreported. That may explain why Mrs. Clinton provided her public assessment while traveling in the Middle East last week.
By the accounts of a number of computer scientists, nuclear enrichment experts and former officials, the covert race to create Stuxnet was a joint project between the Americans and the Israelis, with some help, knowing or unknowing, from the Germans and the British.
The project’s political origins can be found in the last months of the Bush administration. In January 2009, The New York Times reported that Mr. Bush authorized a covert program to undermine the electrical and computer systems around Natanz, Iran’s major enrichment center. President Obama, first briefed on the program even before taking office, sped it up, according to officials familiar with the administration’s Iran strategy. So did the Israelis, other officials said.
There's lots more. How the Americans and Israelis developed the Stuxnet worm and made it so good reads like an espionage thriller.
Further reading: follow link (repeated here (PDF)) within the article for a copy of a DHS briefing put together by a US national lab and Siemens regarding the vulnerability of the control systems that were attacked by Stuxnet.
See Ralph Langner's blog for more good geekery. Langner is identified in the NYT article as one of the people who reverse engineered the Stuxnet worm, shortly after it was detected in the wild.