Tag Archives: cyber attack

The Nightmare of Keeping the Lights On

Some 330 million Americans rely on the nation’s critical infrastructure to keep the country humming. Disruptions to electrical grids, communications systems, and supply chains can be catastrophic, yet all of these are vulnerable to cyberattack. According to the government’s 2019 World Wide Threats Hearing, certain adversaries are capable of launching cyberattacks that can disrupt the nation’s critical infrastructure – including electrical distribution networks.

In recognition of the disruptions cyberattacks can cause, DARPA in 2016 established the Rapid Attack Detection, Isolation and Characterization Systems (RADICS) program. The goal of RADICS has been to enable black-start recovery during a cyberattack. Black start is the process of restoring power to an electric substation or part of the grid that has experienced a total or partial shutdown without relying on an external power transmission network to get things back online…

“Cyberattacks on the grid can essentially do two things – make the grid not tell you the truth, and make the grid operate in an unexpected way,” said Walter Weiss, the program manager responsible for RADICS. “For example, the grid could show you that a substation has power when in reality it does not. This could unintentionally prevent power restoration to an entire area since no one thinks there is a need to bring power back online. The technologies developed under RADICS help provide ground truth around grid status, giving responders the ability to quickly detect anomalies and then chart a path towards recovery.”…

 The RADICS testbed is comprised of miniaturized substations that were designed to operate as they do in the real world, but with safeguards to protect the system and those operating the substations. The substations are connected via power lines, forming a multi-utility crank path. With a crank path, power is generated to black start one utility that then powers the next utility and the next until the grid is fully restored.

DARPA substation, Plum island NY

Technologies to Rapidly Restore the Electrical Grid after Cyberattack Come Online, DARPA Website, Feb. 23, 2021

Who is the Boss? Cyber-War

A new National Cyber Power Index by the Belfer Centre at Harvard University ranks 30 countries on their level of ambition and capability…That America stands at the top of the list is not surprising. Its cyber-security budget for fiscal year 2020 stood at over $17bn and the National Security Agency (NSA) probably gets well over $10bn. The awesome scale of America’s digital espionage was laid bare in leaks by Edward Snowden, a former NSA contractor, in 2013, which showed the agency hoovering up vast amounts of the world’s internet traffic and trying to weaken encryption standards.

China, in second place, has demonstrated a voracious appetite for commercial cyber-espionage abroad and an iron grip on the internet at home. Britain, whose National Cyber Security Centre has parried over 1,800 cyber-attacks since its creation in 2016, is third. Russia, whose spies interfered with America’s last election, is in fourth place. The big surprise is the Netherlands in fifth place, ahead of France, Germany and Canada. Dutch expertise in analyzing malware is particularly sharp…

Many countries outsource the dirtiest work to deniable proxies, like “hacktivists” and criminals….But while stealing things and disrupting networks is important, what matters most over the longer term is control of digital infrastructure, such as the hardware that runs mobile telecommunications and key apps. Dominance there will be crucial to economic strength and national security.

Excerpt from Digital dominance: A new global ranking of cyber-power throws up some surprises, Economist, Sept. 19, 2020

Firing Back with Vengeance: the NSA Weapons

The strike on IDT, a conglomerate,… was similar to WannaCry in one way: Hackers locked up IDT data and demanded a ransom to unlock it.  But the ransom demand was just a smoke screen for a far more invasive attack that stole employee credentials. With those credentials in hand, hackers could have run free through the company’s computer network, taking confidential information or destroying machines….Were it not for a digital black box that recorded everything on IDT’s network, …the attack might have gone unnoticed.

Scans for the two hacking tools used against IDT indicate that the company is not alone. In fact, tens of thousands of computer systems all over the world have been “backdoored” by the same N.S.A. weapons. Mr. Ben-Oni and other security researchers worry that many of those other infected computers are connected to transportation networks, hospitals, water treatment plants and other utilities…

Both WannaCry and the IDT attack used a hacking tool the agency had code-named EternalBlue. The tool took advantage of unpatched Microsoft servers to automatically spread malware from one server to another, so that within 24 hours… hackers had spread their ransomware to more than 200,000 servers around the globe. The attack on IDT went a step further with another stolen N.S.A. cyberweapon, called DoublePulsar. The N.S.A. used DoublePulsar to penetrate computer systems without tripping security alarms. It allowed N.S.A. spies to inject their tools into the nerve center of a target’s computer system, called the kernel, which manages communications between a computer’s hardware and its software.

In the pecking order of a computer system, the kernel is at the very top, allowing anyone with secret access to it to take full control of a machine. It is also a dangerous blind spot for most security software, allowing attackers to do what they want and go unnoticed. In IDT’s case, attackers used DoublePulsar to steal an IDT contractor’s credentials. Then they deployed ransomware in what appears to be a cover for their real motive: broader access to IDT’s businesses…

But the attack struck Mr. Ben-Oni as unique. For one thing, it was timed perfectly to the Sabbath. Attackers entered IDT’s network at 6 p.m. on Saturday on the dot, two and a half hours before the Sabbath would end and when most of IDT’s employees — 40 percent of whom identify as Orthodox Jews — would be off the clock. For another, the attackers compromised the contractor’s computer through her home modem — strange.

The black box of sorts, a network recording device made by the Israeli security company Secdo, shows that the ransomware was installed after the attackers had made off with the contractor’s credentials. And they managed to bypass every major security detection mechanism along the way. Finally, before they left, they encrypted her computer with ransomware, demanding $130 to unlock it, to cover up the more invasive attack on her computer.

A month earlier, Microsoft had issued a software patch to defend against the N.S.A. hacking tools — suggesting that the agency tipped the company off to what was coming. Microsoft regularly credits those who point out vulnerabilities in its products, but in this case the company made no mention of the tipster. Later, when the WannaCry attack hit hundreds of thousands of Microsoft customers, Microsoft’s president, Brad Smith, slammed the government in a blog post for hoarding and stockpiling security vulnerabilities.  For his part, Mr. Ben-Oni said he had rolled out Microsoft’s patches as soon as they became available, but attackers still managed to get in through the IDT contractor’s home modem.

There are now YouTube videos showing criminals how to attack systems using the very same N.S.A. tools used against IDT, and Metasploit, an automated hacking tool, now allows anyone to carry out these attacks with the click of a button….

“Once DoublePulsar is on the machine, there’s nothing stopping anyone else from coming along and using the back door,” Mr. Dillon said.More distressing, Mr. Dillon tested all the major antivirus products against the DoublePulsar infection and a demoralizing 99 percent failed to detect it.  “We’ve seen the same computers infected with DoublePulsar for two months and there is no telling how much malware is on those systems,” Mr. Dillon said. “Right now we have no idea what’s gotten into these organizations.”..

Could that attack be coming? The Shadow Brokers resurfaced last month, promising a fresh load of N.S.A. attack tools, even offering to supply them for monthly paying subscribers — like a wine-of-the-month club for cyberweapon enthusiasts.

Excerpts from NICOLE PERLROTHJUNE, A Cyberattack ‘the World Isn’t Ready For’,  New York Times, June 20, 2017

Cyberwar: government hackers

The mysterious hacking group that supplied a critical component of the WannaCry “ransomware” software attack that spread across the globe in mid-May 2017 has been releasing alleged National Security Agency secrets for the past eight months.  Former intelligence officials now fear that the hackers, who go by the name Shadow Brokers, are taking a new tack: exposing the identities of the NSA’s computer-hacking team. That potentially could subject these government experts to charges when traveling abroad.

The Shadow Brokers on April 14, 2017 posted on a Russian computer file-sharing site what they said were NSA files containing previously unknown attack tools and details of an alleged NSA hack affecting Middle Eastern and Panamanian financial institutions.

But something went largely unnoticed outside the intelligence community. Buried in the files’ “metadata”—a hidden area that typically lists a file’s creators and editors—were four names. It isn’t clear whether the names were published intentionally or whether the files were doctored. At least one person named in the metadata worked for the NSA, a person familiar with the matter said.  Additionally, the hacking group in April, 2017 sent several public tweets that seemingly threatened to expose the activities of a fifth person, former NSA employee Jake Williams, who had written a blog post speculating the group has ties to Russia… Security experts who have examined the documents believe they contain legitimate information, including code that can be used in hacks, as well as the names of the files’ creators and editors.

Because nation-state hackers might run afoul of other countries’ laws while discharging their duties, they could, if identified, face charges when outside their country. So, to keep their own people safe, governments for decades have abided by a “gentleman’s agreement” that allows government-backed hackers to operate in anonymity, former intelligence officials say….

Some former intelligence officials suggested the U.S. prompted the outing of state-sponsored hackers when it indicted five Chinese military hackers by name in 2014, and more recently brought charges against two officers with Russia’s Federal Security Service over a 2014 Yahoo Inc. breach.  By exposing cyberagents, the Shadow Brokers appear to be taking a page from the U.S. playbook, said Mr. Williams, who worked for the NSA’s Tailored Access Operations hacking group until 2013. An NSA spokesman said the agency doesn’t comment about “most individuals’ possible current, past or future employment with the agency.”  “We’ve fired first,” Mr. Williams said, referring to the U.S. charging the alleged Chinese hackers by name. “This is us taking flak.”…

The documents revealed jealously guarded tactics and techniques the NSA uses to access computer systems…For example, the files include source code for software designed to give its creators remote access to hacked machines, and to evade detection from antivirus software. If the code was created by the NSA, it now gives security professionals a digital fingerprint they can use to track the NSA’s activities prior to the leak.

That could prove disruptive to NSA activities, forcing the agency to consider pulling its software from others’ networks and taking other steps to erase its tracks. And while the information could help companies determine whether they have been hacked by the NSA, it could also be used to create more malicious software. The Shadow Brokers tools, for example, are now being used to install malicious software such as WannaCry on corporate networks.

Mr. Williams initially thought the Shadow Brokers had access only to a limited set of NSA tools. His assessment changed after three tweets directed at him April 9, 2017 included terms suggesting the group had “a lot of operational data or at least operational insight” into his work at the NSA, he said.  The tweets, which are public, are cryptic. They express displeasure over an article Mr. Williams wrote attempting to link the Shadow Brokers to Russia. They also mention apparent software code names, including “OddJob” and “Windows BITS persistence.”…..OddJob is a reference to software released by the Shadow Brokers five days after the tweets. “Windows BITS persistence” is a term whose meaning isn’t publicly known.

Excerpts from In Modern Cyber War, the Spies Can Become Targets, Too, Wall Street Journal, May 25, 2017

 

Power Grid: smart and sensitive

Raytheon Company  and Utilidata have formed a strategic alliance to help power utilities proactively detect, defend against and respond to cyber threats.  The effort will combine Utilidata’s experience in the use of real-time data from the electrical grid to detect and respond to cyber attacks and Raytheon’s expertise in proactive cyber threat hunting, automation and managed security services to provide world-class cybersecurity, analytics and other innovative technologies….

[According to] Scott DePasquale, chairman and CEO of Utilidata. “With more and more devices and systems connected to the internet, and all of them needing electrical power, these challenges are increasing exponentially. This new alliance will help define the future of cybersecurity in the power utilities sector.”  In December 2015, a cyber attack shut down a large section of the Ukrainian power grid – an incident that the Department of Energy identified in the 2017 installment of the Quadrennial Energy Review as an ‘indicator of what is possible.’

Excerpts from  Raytheon, Utilidata to deliver defense-grade cybersecurity for utilities, PRNewswire, Feb. 8, 2017

Hacking the Power Grid

In Ukraine on Dec. 23, 2015 the power suddenly went out for thousands of people in the capital, Kiev, and western parts of the country. While technicians struggled for several hours to turn the lights back on, frustrated customers got nothing but busy signals at their utilities’ call centers….Hackers had taken down almost a quarter of the country’s power grid, claimed Ukrainian officials.  Specifically, the officials blamed Russians for tampering with the utilities’ software, then jamming the power companies’ phone lines to keep customers from alerting anyone….Several of the firms researching the attack say signs point to Russians as the culprits. The malware found in the Ukrainian grid’s computers, BlackEnergy3, is a known weapon of only one hacking group—dubbed Sandworm by researcher ISight Partners—whose attacks closely align with the interests of the Russian government. The group carried out attacks against the Ukrainian government and NATO in 2014…

The more automated U.S. and European power grids are much tougher targets. To cloak Manhattan in darkness, hackers would likely need to discover flaws in the systems the utilities themselves don’t know exist before they could exploit them. In the Ukrainian attack, leading security experts believe the hackers simply located the grid controls and delivered a command that shut the power off. Older systems may be more vulnerable to such attacks, as modern industrial control software is better at recognizing and rejecting unauthorized commands, says IOActive’s Larsen.

That said, a successful hack of more advanced U.S. or European systems would be a lot harder to fix. Ukrainian utility workers restored power by rushing to each disabled substation and resetting circuit breakers manually. Hackers capable of scrambling New York’s power plant software would probably have to bypass safety mechanisms to run a generator or transformer hotter than normal, physically damaging the equipment. That could keep a substation offline for days or weeks, says Michael Assante, former chief security officer for the nonprofit North American Electric Reliability.

Hackers may have targeted Ukraine’s grid for the same reason NATO jets bombed Serbian power plants in 1999: to show the citizenry that its government was too weak to keep the lights on. The hackers may even have seen the attack as in-kind retaliation after sabotage left 1.2 million people in Kremlin-controlled Crimea without lights in November 2015. In that case, saboteurs blew up pylons with explosives, then attacked the repair crews that came to fix them, creating a blackout that lasted for days. Researchers will continue to study the cyber attack in Ukraine, but the lesson may be that when it comes to war, a bomb still beats a keyboard.

Excerpts How Hackers Took Down a Power Grid, Bloomberg Business Week, Jan. 14, 2016

Forecast a CyberAtttack: IARPA

From the website of IARPA (Intelligence Advanced Research Projects Activity (IARPA) — a US research agency under the Director of National Intelligence.

“Approaches to cyber defense typically focus on post-mortem analysis of the various attack vectors utilized by adversaries. As attacks have evolved and increased over the years, established approaches (e.g., signature-based detection, anomaly detection) have not adequately enabled cybersecurity practitioners to get ahead of these threats. This has led to an industry that has invested heavily in analyzing the effects of cyber-attacks instead of analyzing and mitigating the “cause” of cyber-attacks,

The CAUSE   (Cyber-attack Automated Unconventional Sensor Environment)Program seeks to develop cyber-attack forecasting methods and detect emerging cyber phenomena to assist cyber defenders with the earliest detection of a cyber-attack (e.g., Distributed Denial of Service (DDoS), successful spearphishing, successful drive-by, remote exploitation, unauthorized access, reconnaissance). T

he CAUSE Program aims to develop and validate unconventional multi-disciplined sensor technology (e.g., actor behavior models, black market sales) that will forecast cyber-attacks and complement existing advanced intrusion detection capabilities. Anticipated innovations include: methods to manage and extract huge amounts of streaming and batch data, the application and introduction of new and existing features from other disciplines to the cyber domain, and the development of models to generate probabilistic warnings for future cyber events. Successful proposers will combine cutting-edge research with the ability to develop robust forecasting capabilities from multiple sensors not typically used in the cyber domain…”

Excerpt from IARPA website

 

CyberWeapons: Regin Malware

An advanced piece of malware, newly uncovered, has been in use since as early as 2008 to spy on governments, companies and individuals, Symantec said in a report .  The Regin cyberespionage tool uses several stealth features to avoid detection, a characteristic that required a significant investment of time and resources and that suggests it’s the product of a nation-state, Symantec warned, without hazarding a guess about which country might be behind it. The malware’s design makes it highly suited for long-term mass surveillance, according to the maker of antivirus software…

The highly customizable nature of Regin, which Symantec labeled a “top-tier espionage tool,” allows for a wide range of remote access Trojan capabilities, including password and data theft, hijacking the mouse’s point-and-click functions, and capturing screenshots from infected computers. Other infections were identified monitoring network traffic and analyzing email from Exchange databases….

The malware’s targets are geographically diverse, Symantec said, observing more than half of the infections in Russia and Saudi Arabia. Among the other countries targeted are Ireland, Mexico and India. [ Regin have been identified also in Afghanistan, Algeria, Belgium, Brazil, Fiji, Germany,Indonesia, Iran, Kiribati, Malaysia, Pakistan, Syria]

Regin is composed of five attack stages that are hidden and encrypted, with the exception of the first stage, which begins a domino chain of decrypting and executing the next stage. Each individual stage contains little information about malware’s structure. All five stages had to be acquired to analyze the threat posed by the malware.  The multistage architecture of Regin, Symantec said, is reminiscent of Stuxnet, a sophisticated computer virus discovered attacking a nuclear enrichment facility in Iran in 2010, and Duqu, which has identical code to Stuxnet but which appeared designed for cyber espionage instead of sabotage.  Symantec said it believes that many components of Regin remain undiscovered and that additional functionality and versions may exist.  “Regin uses a modular approach,” Symantec said, “giving flexibility to the threat operators as they can load custom features tailored to individual targets when required.”

Excerpt from Steven Musil Stealthy Regin malware is a ‘top-tier espionage tool’, CNET, Nov. 23, 2014

Cyber-Warriors: US and China

On May 19th, 2014 the Justice Department unveiled 31 charges against five members of China’s People’s Liberation Army (PLA), involving breaking six laws, from relatively minor counts of identity theft to economic espionage, which carries a maximum sentence of 15 years. This is the first time the government has charged employees of a foreign government with cybercrime. The accused are unlikely ever to stand trial. Even so, the Justice Department produced posters with mugshots of the men beneath the legend “wanted by the FBI”. They may never be punished, but that is not the point. Google any of their names and the mugshots now appear, the online equivalent of a perp walk.

That China’s government spies on the commercial activities of companies in America is not news in itself. Last year Mandiant, a cyber-security firm based in Virginia, released a report that identified Unit 61398 of the PLA as the source of cyber-attacks against 140 companies since 2006. But the indictment does reveal more details about what sorts of things the Chinese cybersnoops have been snaffling.

Hackers stole designs for pipes from Westinghouse, an American firm, when it was building four nuclear power stations in China, and also took e-mails from executives who were negotiating with a state-owned company. They took financial information from SolarWorld, a maker of solar panels; gained access to computers owned by US Steel while it was in a trade dispute with a state-owned company; and took files from Alcoa, an aluminium producer, while it was in a joint venture with another Chinese government-backed firm. ATI, another metal firm, and the United Steelworkers union were hacked, too.

American firms that do business in China have long lobbied behind closed doors for Uncle Sam to do something about Chinese hackers. America’s government has hitherto followed a similar logic, pressing China in private. The decision to make a fuss reflects the failure of that approach. When the existence of Unit 61398 became public its troops paused for a while, then continued as before.

Confronting the PLA’s hackers comes at a cost. China has pulled out of a bilateral working group on cyber-security in response to the indictments. Global Times, a Chinese English-language daily, denounced America as: “a mincing rascal”. But doing nothing has a cost, too. Companies like Westinghouse and US Steel have a hard enough time competing with Chinese firms, without having their business plans and designs pinched by thieves in uniform. Nor is the spying limited to manufacturers: tech companies have been targeted by the same group…

Second, America’s spying on Huawei, a Chinese maker of telecoms and networking equipment, makes China’s government doubt that America follows its own rules.

Chinese spying: Cybersnoops and mincing rascals,  Economist, May 24, at 28

Cyberwar: USA Official Doctrine

 

In his first major speech [March 28, 2014] on cyber policy, Defense Secretary Chuck Hagel sough to project strength but also to tame perceptions of the United States as an aggressor in computer warfare, stressing that the government “does not seek to militarize cyberspace.”…

Hagel said that the fighting force at U.S. Cyber Command will number more than 6,000 people by 2016, making it one of the largest such ­forces in the world. The force will help expand the president’s options for responding to a crisis with “full-spectrum cyber capabilities,” Hagel said, a reference to cyber operations that can include destroying, damaging or sabotaging an adversary’s computer systems and that can complement other military operations.

But, Hagel said, the military’s first purpose is “to prevent and de-escalate conflict.” The Pentagon will maintain “an approach of restraint to any cyber operations outside of U.S. government networks.”  Although some U.S. adversaries, notably China and Russia, which also have formidable cyber capabilities, may view his remarks with skepticism, Hagel said the Pentagon is making an effort to be “open and transparent” about its cyber­forces and doctrine. The hope, senior officials said, is that transparency will lead to greater stability in cyberspace.  To underscore the point, Hagel’s speech was broadcast live from NSA headquarters at Fort Meade, the first such broadcast from the agency…

Tensions over U.S. cyber operations intensified again last weekend after a report that the NSA had penetrated the networks of a Chinese telecommunications giant, Huawei Technologies, in search of evidence that it was involved in espionage operations for Beijing and to use its equipment to spy on adversaries such as Iran. After the disclosure, first reported by the New York Times and Der Spiegel, China demanded a halt to any such activity and called for an explanation…

Analysts said that China and Russia were unlikely to be convinced by Hagel’s remarks. Revelations about the NSA’s activities, based on documents provided by former contractor Edward Snowden, make U.S. assertions that it is focused on protecting U.S. national security — and not actively infiltrating others’ networks — that much harder to accept, they said.

Excerpts from: Ellen Nakashima, U.S. cyberwarfare force to grow significantly, defense secretary says, Washington Post, Mar. 28, 2014

See also http://www.defense.gov/news/newsarticle.aspx?id=121928

 

United States, Iran and the Stuxnet Worm

From his first months in office, President Obama secretly ordered increasingly sophisticated attacks on the computer systems that run Iran’s main nuclear enrichment facilities, significantly expanding America’s first sustained use of cyberweapons, according to participants in the program.  Mr. Obama decided to accelerate the attacks — begun in the Bush administration and code-named Olympic Games — even after an element of the program accidentally became public in the summer of 2010 because of a programming error that allowed it to escape Iran’s Natanz plant and sent it around the world on the Internet. Computer security experts who began studying the worm, which had been developed by the United States and Israel, gave it a name: Stuxnet.  At a tense meeting in the White House Situation Room within days of the worm’s “escape,” Mr. Obama, Vice President Joseph R. Biden Jr. and the director of the Central Intelligence Agency at the time, Leon E. Panetta, considered whether America’s most ambitious attempt to slow the progress of Iran’s nuclear efforts had been fatally compromised.  “Should we shut this thing down?” Mr. Obama asked, according to members of the president’s national security team who were in the room.  Told it was unclear how much the Iranians knew about the code, and offered evidence that it was still causing havoc, Mr. Obama decided that the cyberattacks should proceed. In the following weeks, the Natanz plant was hit by a newer version of the computer worm, and then another after that. The last of that series of attacks, a few weeks after Stuxnet was detected around the world, temporarily took out nearly 1,000 of the 5,000 centrifuges Iran had spinning at the time to purify uranium.

This account of the American and Israeli effort to undermine the Iranian nuclear program is based on interviews over the past 18 months with current and former American, European and Israeli officials involved in the program, as well as a range of outside experts. None would allow their names to be used because the effort remains highly classified, and parts of it continue to this day.  These officials gave differing assessments of how successful the sabotage program was in slowing Iran’s progress toward developing the ability to build nuclear weapons. Internal Obama administration estimates say the effort was set back by 18 months to two years, but some experts inside and outside the government are more skeptical, noting that Iran’s enrichment levels have steadily recovered, giving the country enough fuel today for five or more weapons, with additional enrichment.

Whether Iran is still trying to design and build a weapon is in dispute. The most recent United States intelligence estimate concludes that Iran suspended major parts of its weaponization effort after 2003, though there is evidence that some remnants of it continue.

Iran initially denied that its enrichment facilities had been hit by Stuxnet, then said it had found the worm and contained it. Last year, the nation announced that it had begun its own military cyberunit, and Brig. Gen. Gholamreza Jalali, the head of Iran’s Passive Defense Organization, said that the Iranian military was prepared “to fight our enemies” in “cyberspace and Internet warfare.” But there has been scant evidence that it has begun to strike back.

The United States government only recently acknowledged developing cyberweapons, and it has never admitted using them. There have been reports of one-time attacks against personal computers used by members of Al Qaeda, and of contemplated attacks against the computers that run air defense systems, including during the NATO-led air attack on Libya last year. But Olympic Games was of an entirely different type and sophistication.

It appears to be the first time the United States has repeatedly used cyberweapons to cripple another country’s infrastructure, achieving, with computer code, what until then could be accomplished only by bombing a country or sending in agents to plant explosives. The code itself is 50 times as big as the typical computer worm, Carey Nachenberg, a vice president of Symantec, one of the many groups that have dissected the code, said at a symposium at Stanford University in April. Those forensic investigations into the inner workings of the code, while picking apart how it worked, came to no conclusions about who was responsible.

A similar process is now under way to figure out the origins of another cyberweapon called Flame that was recently discovered to have attacked the computers of Iranian officials, sweeping up information from those machines. But the computer code appears to be at least five years old, and American officials say that it was not part of Olympic Games. They have declined to say whether the United States was responsible for the Flame attack.

Mr. Obama, according to participants in the many Situation Room meetings on Olympic Games, was acutely aware that with every attack he was pushing the United States into new territory, much as his predecessors had with the first use of atomic weapons in the 1940s, of intercontinental missiles in the 1950s and of drones in the past decade. He repeatedly expressed concerns that any American acknowledgment that it was using cyberweapons — even under the most careful and limited circumstances — could enable other countries, terrorists or hackers to justify their own attacks.

“We discussed the irony, more than once,” one of his aides said. Another said that the administration was resistant to developing a “grand theory for a weapon whose possibilities they were still discovering.” Yet Mr. Obama concluded that when it came to stopping Iran, the United States had no other choice.If Olympic Games failed, he told aides, there would be no time for sanctions and diplomacy with Iran to work. Israel could carry out a conventional military attack, prompting a conflict that could spread throughout the region.

The impetus for Olympic Games dates from 2006, when President George W. Bush saw few good options in dealing with Iran. At the time, America’s European allies were divided about the cost that imposing sanctions on Iran would have on their own economies. Having falsely accused Saddam Hussein of reconstituting his nuclear program in Iraq, Mr. Bush had little credibility in publicly discussing another nation’s nuclear ambitions. The Iranians seemed to sense his vulnerability, and, frustrated by negotiations, they resumed enriching uranium at an underground site at Natanz, one whose existence had been exposed just three years before.

Iran’s president, Mahmoud Ahmadinejad, took reporters on a tour of the plant and described grand ambitions to install upward of 50,000 centrifuges. For a country with only one nuclear power reactor — whose fuel comes from Russia — to say that it needed fuel for its civilian nuclear program seemed dubious to Bush administration officials. They feared that the fuel could be used in another way besides providing power: to create a stockpile that could later be enriched to bomb-grade material if the Iranians made a political decision to do so.  Hawks in the Bush administration like Vice President Dick Cheney urged Mr. Bush to consider a military strike against the Iranian nuclear facilities before they could produce fuel suitable for a weapon. Several times, the administration reviewed military options and concluded that they would only further inflame a region already at war, and would have uncertain results.

For years the C.I.A. had introduced faulty parts and designs into Iran’s systems — even tinkering with imported power supplies so that they would blow up — but the sabotage had had relatively little effect. General James E. Cartwright, who had established a small cyberoperation inside the United States Strategic Command, which is responsible for many of America’s nuclear forces, joined intelligence officials in presenting a radical new idea to Mr. Bush and his national security team. It involved a far more sophisticated cyberweapon than the United States had designed before.

The goal was to gain access to the Natanz plant’s industrial computer controls. That required leaping the electronic moat that cut the Natanz plant off from the Internet — called the air gap, because it physically separates the facility from the outside world. The computer code would invade the specialized computers that command the centrifuges.  The first stage in the effort was to develop a bit of computer code called a beacon that could be inserted into the computers, which were made by the German company Siemens and an Iranian manufacturer, to map their operations. The idea was to draw the equivalent of an electrical blueprint of the Natanz plant, to understand how the computers control the giant silvery centrifuges that spin at tremendous speeds. The connections were complex, and unless every circuit was understood, efforts to seize control of the centrifuges could fail.

Eventually the beacon would have to “phone home” — literally send a message back to the headquarters of the National Security Agency that would describe the structure and daily rhythms of the enrichment plant. Expectations for the plan were low; one participant said the goal was simply to “throw a little sand in the gears” and buy some time. Mr. Bush was skeptical, but lacking other options, he authorized the effort.  It took months for the beacons to do their work and report home, complete with maps of the electronic directories of the controllers and what amounted to blueprints of how they were connected to the centrifuges deep underground.  Then the N.S.A. and a secret Israeli unit respected by American intelligence officials for its cyberskills set to work developing the enormously complex computer worm that would become the attacker from within.  The unusually tight collaboration with Israel was driven by two imperatives. Israel’s Unit 8200, a part of its military, had technical expertise that rivaled the N.S.A.’s, and the Israelis had deep intelligence about operations at Natanz that would be vital to making the cyberattack a success. But American officials had another interest, to dissuade the Israelis from carrying out their own pre-emptive strike against the Iranian nuclear facilities. To do that, the Israelis would have to be convinced that the new line of attack was working. The only way to convince them, several officials said in interviews, was to have them deeply involved in every aspect of the program.

Soon the two countries had developed a complex worm that the Americans called “the bug.” But the bug needed to be tested. So, under enormous secrecy, the United States began building replicas of Iran’s P-1 centrifuges, an aging, unreliable design that Iran purchased from Abdul Qadeer Khan, the Pakistani nuclear chief who had begun selling fuel-making technology on the black market. Fortunately for the United States, it already owned some P-1s, thanks to the Libyan dictator, Col. Muammar el-Qaddafi.  When Colonel Qaddafi gave up his nuclear weapons program in 2003, he turned over the centrifuges he had bought from the Pakistani nuclear ring, and they were placed in storage at a weapons laboratory in Tennessee. The military and intelligence officials overseeing Olympic Games borrowed some for what they termed “destructive testing,” essentially building a virtual replica of Natanz, but spreading the test over several of the Energy Department’s national laboratories to keep even the most trusted nuclear workers from figuring out what was afoot.

Those first small-scale tests were surprisingly successful: the bug invaded the computers, lurking for days or weeks, before sending instructions to speed them up or slow them down so suddenly that their delicate parts, spinning at supersonic speeds, self-destructed. After several false starts, it worked. One day, toward the end of Mr. Bush’s term, the rubble of a centrifuge was spread out on the conference table in the Situation Room, proof of the potential power of a cyberweapon. The worm was declared ready to test against the real target: Iran’s underground enrichment plant.

“Previous cyberattacks had effects limited to other computers,” Michael V. Hayden, the former chief of the C.I.A., said, declining to describe what he knew of these attacks when he was in office. “This is the first attack of a major nature in which a cyberattack was used to effect physical destruction,” rather than just slow another computer, or hack into it to steal data…  Getting the worm into Natanz, however, was no easy trick. The United States and Israel would have to rely on engineers, maintenance workers and others — both spies and unwitting accomplices — with physical access to the plant. “That was our holy grail,” one of the architects of the plan said. “It turns out there is always an idiot around who doesn’t think much about the thumb drive in their hand.”

In fact, thumb drives turned out to be critical in spreading the first variants of the computer worm; later, more sophisticated methods were developed to deliver the malicious code.  The first attacks were small, and when the centrifuges began spinning out of control in 2008, the Iranians were mystified about the cause, according to intercepts that the United States later picked up. “The thinking was that the Iranians would blame bad parts, or bad engineering, or just incompetence,” one of the architects of the early attack said.  The Iranians were confused partly because no two attacks were exactly alike. Moreover, the code would lurk inside the plant for weeks, recording normal operations; when it attacked, it sent signals to the Natanz control room indicating that everything downstairs was operating normally. “This may have been the most brilliant part of the code,” one American official said.

Later, word circulated through the International Atomic Energy Agency, the Vienna-based nuclear watchdog, that the Iranians had grown so distrustful of their own instruments that they had assigned people to sit in the plant and radio back what they saw.  “The intent was that the failures should make them feel they were stupid, which is what happened,” the participant in the attacks said. When a few centrifuges failed, the Iranians would close down whole “stands” that linked 164 machines, looking for signs of sabotage in all of them. “They overreacted,” one official said. “We soon discovered they fired people.”

Imagery recovered by nuclear inspectors from cameras at Natanz — which the nuclear agency uses to keep track of what happens between visits — showed the results. There was some evidence of wreckage, but it was clear that the Iranians had also carted away centrifuges that had previously appeared to be working well.  But by the time Mr. Bush left office, no wholesale destruction had been accomplished. Meeting with Mr. Obama in the White House days before his inauguration, Mr. Bush urged him to preserve two classified programs, Olympic Games and the drone program in Pakistan. Mr. Obama took Mr. Bush’s advice….

But the good luck did not last. In the summer of 2010, shortly after a new variant of the worm had been sent into Natanz, it became clear that the worm, which was never supposed to leave the Natanz machines, had broken free, like a zoo animal that found the keys to the cage. It fell to Mr. Panetta and two other crucial players in Olympic Games — General Cartwright, the vice chairman of the Joint Chiefs of Staff, and Michael J. Morell, the deputy director of the C.I.A. — to break the news to Mr. Obama and Mr. Biden.

“I don’t think we have enough information,” Mr. Obama told the group that day, according to the officials. But in the meantime, he ordered that the cyberattacks continue. They were his best hope of disrupting the Iranian nuclear program unless economic sanctions began to bite harder and reduced Iran’s oil revenues.

American cyberattacks are not limited to Iran, but the focus of attention, as one administration official put it, “has been overwhelmingly on one country.” There is no reason to believe that will remain the case for long. Some officials question why the same techniques have not been used more aggressively against North Korea. Others see chances to disrupt Chinese military plans, forces in Syria on the way to suppress the uprising there, and Qaeda operations around the world. “We’ve considered a lot more attacks than we have gone ahead with,” one former intelligence official said….

Mr. Obama has repeatedly told his aides that there are risks to using — and particularly to overusing — the weapon. In fact, no country’s infrastructure is more dependent on computer systems, and thus more vulnerable to attack, than that of the United States. It is only a matter of time, most experts believe, before it becomes the target of the same kind of weapon that the Americans have used, secretly, against Iran.

DAVID E. SANGER,Obama Order Sped Up Wave of Cyberattacks Against Iran, New York Times, June 1, 2012