Israeli Test on Worm Called Crucial in Iran Nuclear Delay
By WILLIAM J. BROAD, JOHN MARKOFF and DAVID E. SANGER
Published: January 15, 2011
This article is by William J. Broad, John Markoff and David E. Sanger.
Over the past two years, according to intelligence and military experts familiar with its operations, Dimona has taken on a new, equally secret role — as a critical testing ground in a joint American and Israeli effort to undermine Iran’s efforts to make a bomb of its own.
Behind Dimona’s barbed wire, the experts say,
“To check out the worm, you have to know the machines,” said an American expert on nuclear intelligence. “The reason the worm has been effective is that the Israelis tried it out.”
Though American and Israeli officials refuse to talk publicly about what goes on at Dimona, 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
The gruff Mr. Dagan, whose organization has been accused by
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.
Many mysteries remain, chief among them, exactly who constructed a computer worm that appears to have several authors on several continents. But the digital trail is littered with intriguing bits of evidence.
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.
Siemens says that program was part of routine efforts to secure its products against cyberattacks. Nonetheless, it gave the Idaho National Laboratory — which is part of the Energy Department, responsible for
The worm itself now appears to have included two major components. One was designed to send
The attacks were not fully successful: Some parts of
“It’s like a playbook,” said Ralph Langner, an independent computer security expert in
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
In recent days, American officials who spoke on the condition of anonymity have said in interviews that they believe
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
Two years ago, when Israel still thought its only solution was a military one and approached Mr. Bush for the bunker-busting bombs and other equipment it believed it would need for an air attack, its officials told the White House that such a strike would set back Iran’s programs by roughly three years. Its request was turned down.
Now, Mr. Dagan’s statement suggests that
Paranoia helped, as it turns out.
Years before the worm hit
Computers known as controllers run all kinds of industrial machinery. By early 2008, theDepartment of Homeland Security had teamed up with the Idaho National Laboratory to study a widely used Siemens controller known as P.C.S.-7, for Process Control System 7. Its complex software, called Step 7, can run whole symphonies of industrial instruments, sensors and machines.
The vulnerability of the controller to cyberattack was an open secret. In July 2008, the
“Goal is for attacker to gain control,” the July paper said in describing the many kinds of maneuvers that could exploit system holes. The paper was 62 pages long, including pictures of the controllers as they were examined and tested in
In a statement on Friday, the Idaho National Laboratory confirmed that it formed a partnership with Siemens but said it was one of many with manufacturers to identify cybervulnerabilities. It argued that the report did not detail specific flaws that attackers could exploit. But it also said it could not comment on the laboratory’s classified missions, leaving unanswered the question of whether it passed what it learned about the Siemens systems to other parts of the nation’s intelligence apparatus.
The presentation at the
Controllers, and the electrical regulators they run, became a focus of sanctions efforts. The trove of State Department cables made public by WikiLeaks describes urgent efforts in April 2009 to stop a shipment of Siemens controllers, contained in 111 boxes at the port of Dubai, in the United Arab Emirates. They were headed for
Subsequent cables showed that the
Only months later, in June, Stuxnet began to pop up around the globe. The Symantec Corporation, a maker of computer security software and services based in
But unlike most malware, it seemed to be doing little harm. It did not slow computer networks or wreak general havoc.
That deepened the mystery.
A ‘Dual Warhead’
No one was more intrigued than Mr. Langner, a former psychologist who runs a small computer security company in a suburb of
He quickly discovered that the worm only kicked into gear when it detected the presence of a specific configuration of controllers, running a set of processes that appear to exist only in a centrifuge plant. “The attackers took great care to make sure that only their designated targets were hit,” he said. “It was a marksman’s job.”
For example, one small section of the code appears designed to send commands to 984 machines linked together.
Curiously, when international inspectors visited Natanz in late 2009, they found that the Iranians had taken out of service a total of exactly 984 machines that had been running the previous summer.
But as Mr. Langner kept peeling back the layers, he found more — what he calls the “dual warhead.” One part of the program is designed to lie dormant for long periods, then speed up the machines so that the spinning rotors in the centrifuges wobble and then destroy themselves. Another part, called a “man in the middle” in the computer world, sends out those false sensor signals to make the system believe everything is running smoothly. That prevents a safety system from kicking in, which would shut down the plant before it could self-destruct.
“Code analysis makes it clear that Stuxnet is not about sending a message or proving a concept,” Mr. Langner later wrote. “It is about destroying its targets with utmost determination in military style.”
This was not the work of hackers, he quickly concluded. It had to be the work of someone who knew his way around the specific quirks of the Siemens controllers and had an intimate understanding of exactly how the Iranians had designed their enrichment operations.
In fact, the Americans and the Israelis had a pretty good idea.
Testing the Worm
Perhaps the most secretive part of the Stuxnet story centers on how the theory of cyberdestruction was tested on enrichment machines to make sure the malicious software did its intended job.
The account starts in the Netherlands. In the 1970s, the Dutch designed a tall, thin machine for enriching uranium. As is well known, A. Q. Khan, a Pakistani metallurgist working for the Dutch, stole the design and in 1976 fled to Pakistan.
The resulting machine, known as the P-1, for Pakistan’s first-generation centrifuge, helped the country get the bomb. And when Dr. Khan later founded an atomic black market, he illegally sold P-1’s to Iran, Libya, and North Korea.
The P-1 is more than six feet tall. Inside, a rotor of aluminum spins uranium gas to blinding speeds, slowly concentrating the rare part of the uranium that can fuel reactors and bombs.
How and when Israel obtained this kind of first-generation centrifuge remains unclear, whether from Europe, or the Khan network, or by other means. But nuclear experts agree that Dimona came to hold row upon row of spinning centrifuges.
“They’ve long been an important part of the complex,” said Avner Cohen, author of “The Worst-Kept Secret” (2010), a book about the Israeli bomb program, and a senior fellow at the Monterey Institute of International Studies. He added that Israeli intelligence had asked retired senior Dimona personnel to help on the Iranian issue, and that some apparently came from the enrichment program.
“I have no specific knowledge,” Dr. Cohen said of Israel and the Stuxnet worm. “But I see a strong Israeli signature and think that the centrifuge knowledge was critical.”
Another clue involves the United States. It obtained a cache of P-1’s after Libya gave up its nuclear program in late 2003, and the machines were sent to the Oak Ridge National Laboratory in Tennessee, another arm of the Energy Department.
By early 2004, a variety of federal and private nuclear experts assembled by the Central Intelligence Agency were calling for the United States to build a secret plant where scientists could set up the P-1’s and study their vulnerabilities. “The notion of a test bed was really pushed,” a participant at the C.I.A. meeting recalled.
The resulting plant, nuclear experts said last week, may also have played a role in Stuxnet testing.
But the United States and its allies ran into the same problem the Iranians have grappled with: the P-1 is a balky, badly designed machine. When the Tennessee laboratory shipped some of its P-1’s to England, in hopes of working with the British on a program of general P-1 testing, they stumbled, according to nuclear experts.
“They failed hopelessly,” one recalled, saying that the machines proved too crude and temperamental to spin properly.
Dr. Cohen said his sources told him that Israel succeeded — with great difficulty — in mastering the centrifuge technology. And the American expert in nuclear intelligence, who spoke on the condition of anonymity, said the Israelis used machines of the P-1 style to test the effectiveness of Stuxnet.
The expert added that Israel worked in collaboration with the United States in targeting Iran, but that Washington was eager for “plausible deniability.”
In November, the Iranian president, Mahmoud Ahmadinejad, broke the country’s silence about the worm’s impact on its enrichment program, saying a cyberattack had caused “minor problems with some of our centrifuges.” Fortunately, he added, “our experts discovered it.”
The most detailed portrait of the damage comes from the Institute for Science and International Security, a private group in Washington. Last month, it issued a lengthy Stuxnet report that said Iran’s P-1 machines at Natanz suffered a series of failures in mid- to late 2009 that culminated in technicians taking 984 machines out of action.
The report called the failures “a major problem” and identified Stuxnet as the likely culprit.
Stuxnet is not the only blow to Iran. Sanctions have hurt its effort to build more advanced (and less temperamental) centrifuges. And last January, and again in November, two scientists who were believed to be central to the nuclear program were killed in Tehran.
The man widely believed to be responsible for much of Iran’s program, Mohsen Fakrizadeh, a college professor, has been hidden away by the Iranians, who know he is high on the target list.
Publicly, Israeli officials make no explicit ties between Stuxnet and Iran’s problems. But in recent weeks, they have given revised and surprisingly upbeat assessments of Tehran’s nuclear status.
“A number of technological challenges and difficulties” have beset Iran’s program, Moshe Yaalon, Israel’s minister of strategic affairs, told Israeli public radio late last month.
The troubles, he added, “have postponed the timetable.”
This article has been revised to reflect the following correction:
Correction: January 17, 2011
An earlier version of this story misspelled, at one point, the name of the German company whose computer controller systems were exploited by the Stuxnet computer worm. It is Siemens, not Seimens.
A version of this article appeared in print on January 16, 2011, on page A1 of the New York edition.