Skip to main content

Bits before bombs: How Stuxnet crippled Iran’s nuclear dreams

Image used with permission by copyright holder

The future of warfare may have just begun, but rather than being heralded by an explosion, it began without a sound or a single casualty.

It is the first of its kind, and could be a signal of the ways all wars are fought from now on. It is a cyber weapon so precise that it can destroy a target more effectively than a conventional explosive, and then simply delete itself, leaving the victims left to blame themselves. It is a weapon that is so terrible that it could conceivably do more than just damage physical objects, it could kill ideas. It is the Stuxnet worm, dubbed by many as the world first real weapon of cyberwarfare, and its first target was Iran.

Recommended Videos

The dawn of cyberwarfare

Stuxnet is almost like something out of a Tom Clancy novel. Rather than sending in missiles to destroy a nuclear plant that threatens the entire region and the world, and is overseen by a president who has claimed that he would like to see an entire race of people “wiped off the map,” a simple computer virus can be introduced that will do the job far more effectively. To attack a structure with missiles can lead to war, and besides, buildings can be rebuilt. But to infect a system so completely that the people using it begin to doubt their faith in their own abilities will have far more devastating long-term effects.

In a rare moment of openness from Iran, the nation has confirmed that the Stuxnet malware (the name stems from keywords buried in the code) that was originally discovered in July, has damaged the country’s nuclear ambitions. Although Iran is downplaying the incident, some reports suggest that the worm was so effective, it may have set back the Iranian nuclear program by several years.

Rather than simply infect a system and destroy everything it touches, Stuxnet is far more sophisticated than that, and far more effective as well.

The worm is smart and adaptable. When it enters a new system, it remains dormant and learns the security system of the computer. Once it can operate without raising alarm, it then seeks out very specific targets and begins to attack certain systems. Rather than simply destroy its targets, it does something far more effective—it misleads them.

In a nuclear enrichment program, a centrifuge is a fundamental tool needed to refine the uranium. Each centrifuge built follows the same basic mechanics, but the German manufacturer Siemens offers what many consider to be the best in the industry. Stuxnet sought out the Siemens controllers and took command of the way the centrifuge spins. But rather than simply forcing the machines to spin until they destroyed themselves—which the worm was more than capable of doing—Stuxnet made subtle, and far more devious changes to the machines.

When a uranium sample was inserted into a Stuxnet-infected centrifuge for refinement, the virus would command the machine to spin faster than it was designed for, then suddenly stop. The results were thousands of machines that wore out years ahead of schedule, and more importantly, ruined samples. But the real trick of the virus was that while it was sabotaging the machinery, it would falsify the readings and make it appear as if everything was operating within the expected parameters.

After months of this, the centrifuges began to wear down and break, but as the readings still appeared to be within the norms, the scientists associated with the project began to second guess themselves. Iranian security agents began to investigate the failures, and the staff at the nuclear facilities lived under a cloud of fear and suspicion. This went on for over a year. If the virus had managed to completely avoid detection, it eventually would have deleted itself entirely and left the Iranians wondering what they were doing wrong.

For 17 months, the virus managed to quietly work its way into the Iranian systems, slowly destroying vital samples and damaging necessary equipment. Perhaps more than the damage to the machinery and the samples was the chaos the program was thrown into.

The Iranians grudgingly admit some of the damage

Iranian President Mahmoud Ahmadinejad has claimed that Stuxnet “managed to create problems for a limited number of our centrifuges,” which is a change from Iran’s earlier assertion that the worm had infected 30,000 computers, but had not affected the nuclear facilities. Some reports suggest at the Natanz facility, which houses the Iranian enrichment programs, 5,084 out of 8,856 centrifuges in use at the Iranian nuclear facilities were taken offline, possibly due to damage, and the plant has been forced to shut down at least twice due to the effects of the virus.

Image used with permission by copyright holder

Stuxnet also targeted the Russian-made steam turbine that powers the Bushehr facility, but it appears that the virus was discovered before any real damage could be done. If the virus had not been uncovered, it would eventually have run the RPMs of the turbines too high and caused irreparable damage to the entire power plant. Temperature and cooling systems have also been identified as targets, but the results of the worm on these systems isn’t clear.

The discovery of the worm

In June of this year, the Belarus-based antivirus specialists, VirusBlokAda found a previously unknown malware program on the computer of an Iranian customer. After researching it, the antivirus company discovered that it was specifically designed to target Siemens SCADA (supervisory control and data acquisition) management systems, which are devices used in large-scale manufacturing. The first clue that something was different about this worm was that once the alert had been raised, every company that tried to pass on the alert was subsequently attacked and forced to shut down for at least 24 hours. The methods and reasons for the attacks are still a mystery.

Once the virus had been discovered, companies like Symantec and Kaspersky, two of the largest antivirus companies in the world, as well as several intelligence agencies, began to research Stuxnet, and found results that quickly made it obvious that this was no ordinary malware.

By the end of September, Symantec had discovered that nearly 60-percent of all the machines infected in the world were located in Iran. Once that had been discovered, it became more and more apparent that the virus was not designed simply to cause problems, as many pieces of malware are, but it had a very specific purpose and a target. The level of sophistication was also well above anything seen before, prompting Ralph Langner, the computer security expert who first discovered the virus, to declare that it was “like the arrival of an F-35 into a World War I battlefield”.

How it worked

Stuxnet specifically targets Windows 7 operating systems, which is, not coincidentally, the same operating system used at the Iranian nuclear power plant. The worm uses four zero-day attacks and specifically targets Siemens’ WinCC/PCS 7 SCADA software. A zero-day threat is a vulnerability that is either unknown or unannounced by the manufacturer. These are generally system-critical vulnerabilities, and once they are discovered, immediately patched. In this case, the two of the zero-day elements had been discovered and were close to having a fixes released, but two others had never been discovered by anyone. Once the worm was in the system, it then began to exploit other systems in the local network it was targeting.

As Stuxnet worked its way through the Iranian systems, it was challenged by the system’s security to present a legitimate certificate. The malware then presented two authentic certificates, one from the circuit manufacturer JMicron, and the other from computer hardware manufacturer Realtek. Both companies are located in Taiwan just blocks away from each other, and both certificates were confirmed to have been stolen. These authentic certificates are one of the reasons that the worm was able to remain undetected for so long.

The malware also had the ability to communicate via peer-to-peer sharing when an Internet connection was present, which allowed it to upgrade as necessary and report back its progress. The servers that Stuxnet communicated with were located in Denmark and Malaysia, and both were shut down once the worm was confirmed to have entered the Natanz facility.

As Stuxnet began to spread throughout the Iranian systems, it began to target only the “frequency converters” responsible for centrifuges. Using variable-frequency drives as markers, the worm looked specifically for drives from two vendors: Vacon, which is based in Finland, and Fararo Paya, which is based in Iran. It then monitors the specified frequencies, and only attacks if a system is running between 807Hz and 1210Hz, a fairly rare frequency that explains how the worm could so specifically target Iranian nuclear plants despite spreading around the world. Stuxnet then sets about altering the output frequency, which affects the connected motors. Although at least 15 other Siemens’ systems have reported infection, none have sustained any damage from the worm.

To first reach the nuclear facility, the worm needed to be brought into the system, possibly on a USB drive. Iran uses an “air gap” security system, meaning the facility has no connection to the Internet. This might explain why the worm spread so far, as the only way for it to infect the system is was to target a wide area and act as a Trojan while waiting for an Iranian nuclear employee to receive an infected file away from the facility and physically bring it into the plant. Because of this, it will be almost impossible to know exactly where and when the infection began, as it may have been brought in by several unsuspecting employees.

But where did it come from, and who developed it?

Suspicions of where the worm originated are rampant, and the most likely single suspect is Israel. After thoroughly researching the virus, Kaspersky Labs announced that the level of attack, and the sophistication with which it was executed could only have been carried out “with nation-state support”, which rules out private hacker groups, or even larger groups that have been using hacking as a means to an end, such as the Russian Mafia, which is suspected of creating a Trojan worm responsible for stealing over $1 million from a British bank.

Israel fully admits that it considers cyberwarfare to be a pillar of its defense doctrine, and the group known as Unit 8200, an Israeli defense force considered to be the rough equivalent of the United States’ NSA, would be the most likely group responsible.

Unit 8200 is the largest division in the Israeli Defense Force, and yet the majority of its operations are unknown- even the identity of the Brigadier General in charge of the unit is classified. Among its many exploits, one report claims that during an Israeli airstrike on a suspected Syrian nuclear facility in 2007, Unit 8200 activated a secret cyber kill switch that deactivated large sections of the Syrian radar.

To further lend credence to this theory, in 2009, Israel pushed back the date of when it expects Iran to have rudimentary nuclear weaponry to 2014. This may have been a result of hearing of problems, or it could suggest that Israel knew something no one else did.

The U.S. is also a prime suspect, and in May of this year, Iran claimed to have arrested 30 people it claims were involved in helping the U.S. wage a “cyber war” against Iran. Iran has also claimed that the Bush administration funded a $400 million plan to destabilize Iran by using cyber attacks. Iran has claimed that the Obama administration has continued that same plan, and even sped up some of the projects. Critics have stated that Iran’s claims are simply an excuse to stamp out “undesirables”, and the arrests are one of many points of contentions between Iran and the U.S.

But as the virus continues to be studied and more answers emerged regarding its function, more mysteries are being raised about its origins.

According to Microsoft, the virus would have taken at least 10,000 hours of coding, and taken a team of five people or more, at least six months of dedicated work. Many are now speculating that it would require the combined efforts of several nations’ intelligence communities all working together to create the worm. While the Israelis might have the determination and the technicians, some are claiming that it would require the United States’ level of technology to code the malware. To know the exact nature of the Siemens machinery to the extent that Stuxnet did might suggest German involvement, and the Russians may have been involved in detailing the specs of the Russian machinery used. The worm was tailored to operate on frequencies that involved Finnish components, which suggests that Finland, and perhaps NATO is involved as well. But there are still more mysteries.

The worm was not detected because of its actions at the Iranian nuclear facilities, but rather as a result of the widespread infection of Stuxnet. The central processing core of the Iranian nuclear processing plant is located deep underground, and is totally cut off from the Internet. For the worm to infect the system, it must have been brought in on the computer or a flash drive of a member of the staff. All it would take is a single employee to take work home with them, then return and insert something as innocuous as a flash drive into the computer, and Stuxnet would begin its silent march to the specific machinery it wanted.

But the question then becomes: Why did the people responsible for the virus develop such an incredibly sophisticated cyberweapon, and then release it in what is arguably such a sloppy method? If the goal was to remain undetected, the release of a virus that has the ability to replicate at the speed that it has shown is sloppy. It was a matter of when, not if, the virus would be discovered.

The most likely reason is that the developers simply didn’t care. To plant the malware more carefully would have taken far more time, and the transmission of the worm into the specific systems might take much longer. If a country is looking for immediate results to halt what it might see as an impending attack, then speed might trump caution. The Iranian nuclear plant is the only infected system to report any real damage from Stuxnet, so the risk to other systems seems to be minimal.

So what next?

Siemens has released a detection and removal tool for Stuxnet, but Iran is still struggling to remove the malware completely. As recently as November 23, the Iranian facility of Natanz was forced to shut down, and further delays are expected. Eventually, the nuclear program should be back up and running.

In a separate, but possibly related story, earlier this week two Iranian scientists were killed by separate but identical bomb attacks in Tehran, Iran. At a press conference the following day, President Ahmadinejad told reporters that “Undoubtedly, the hand of the Zionist regime and Western governments is involved in the assassination.”

Earlier today, Iranian officials claimed to have made several arrests in the bombings, and although the suspects identities have not been released, Iran’s Intelligence Minister has said “The three spy agencies of Mossad, CIA and MI6 had a role in the (attacks) and, with the arrest of these people, we will find new clues to arrest other elements,”

The combination of the bombings and the damage caused by the Stuxnet virus should weigh heavily over the upcoming talks between Iran and a six-nation confederation of China, Russia, France, Great Britain, Germany, and the U.S. on December 6 and 7. The talks are meant to continue the dialogue regarding Iran’s possible nuclear ambitions.

Ryan Fleming
Former Digital Trends Contributor
Ryan Fleming is the Gaming and Cinema Editor for Digital Trends. He joined the DT staff in 2009 after spending time covering…
Black Friday’s best PC hardware deal is still live, and you’re sleeping on it
The Ryzen 5 7600X sitting among thermal paste and RAM.

I'm not mad, just disappointed. A couple of weeks ago, I covered the insane deal that essentially allowed you to score a Ryzen 5 7600X -- still one of the best processors you can buy -- for just $105. At the time, I thought, surely, this will sell out in a matter of hours. Who would pass up on a deal this good? And yet, two weeks later to the day, the craziest deal I've seen during all of Black Friday and Cyber Monday is still live on Newegg.

Let me break down the deal again. You can get the Ryzen 5 7600X for $225, which is not a good price. However, you can get an additional $30 off by using promo code DLCDZ342, bringing the price down to $195. The kicker is that you also get a free Team Group MP44L 1TB PCIe 4.0 SSD. That's a $90 hard drive that Newegg is just throwing in with a CPU that's already available for a decent price. The fact that the deal is still live suggests either Newegg has a ton of inventory, or not enough people know about this sale.

Read more
NZXT dismisses PC rental allegations as ‘misconceptions’ while promising changes
The NZXT H7 Flow refreshed PC case showcased at Computex 2024.

NZXT founder and CEO Johnny Hou has publicly addressed growing criticism of the company’s Flex gaming PC rental program, which faced intense scrutiny after YouTube channel Gamers Nexus exposed significant flaws in its pricing and terms. In a detailed video, Gamers Nexus described the program as exploitative, pointing out that its long-term costs far outweighed the hardware's value, leaving customers locked into a financial commitment with minimal ownership options.

“I want to acknowledge that we messed up,” Hou said in a video published by the company. He also promised to address customer concerns and improve the program but offered few specifics on what changes would be implemented.

Read more
ChatGPT’s new Pro subscription will cost you $200 per month
glasses and chatgpt

Sam Altman and team kicked off the company's "12 Days of OpenAI" event Thursday with a live stream to debut the fully functional version of its 01 reasoning model, as well as a new subscription tier called ChatGPT Pro. But to gain unlimited access to these new features and capabilities, you're going to need to shell out an exorbitant $200 per month.

The 01 model, originally codenamed Project Strawberry, was first released in September as a preview, alongside a lighter-weight o1-mini model, to ChatGPT-Plus subscribers. o1, as a reasoning model, differs from standard LLMs in that it is capable of fact-checking itself before returning its generated response to the user. This helps such models reduce their propensity to hallucinate answers but comes at the cost of a longer inference period and slower response.

Read more