Over the past couple of years, cybersecurity firms have been racing to deconstruct the malware—and to work out who’s behind it. Their research paints a worrying picture of a sophisticated cyberweapon built and deployed by a determined and patient hacking group whose identity has yet to be established with certainty.

The hackers appear to have been inside the petrochemical company’s corporate IT network since 2014. From there, they eventually found a way into the plant’s own network, most likely through a hole in a poorly configured digital firewall that was supposed to stop unauthorized access. They then got into an engineering workstation, either by exploiting an unpatched flaw in its Windows code or by intercepting an employee’s login credentials.

Since the workstation communicated with the plant’s safety instrumented systems, the hackers were able to learn the make and model of the systems’ hardware controllers, as well as the versions of their firmware—software that’s embedded in a device’s memory and governs how it communicates with other things.

It’s likely they next acquired an identical Schneider machine and used it to test the malware they developed. This made it possible to mimic the protocol, or set of digital rules, that the engineering workstation used to communicate with the safety systems. The hackers also found a “zero-day vulnerability”, or previously unknown bug, in the Triconex model’s firmware. This let them inject code into the safety systems’ memories that ensured they could access the controllers whenever they wanted to.

Thus, the intruders could have ordered the safety instrumented systems to disable themselves and then used other malware to trigger an unsafe situation at the plant.

The results could have been horrific. The world’s worst industrial disaster to date also involved a leak of poisonous gases. In December 1984 a Union Carbide pesticide plant in Bhopal, India, released a vast cloud of toxic fumes, killing thousands and causing severe injuries to many more. The cause that time was poor maintenance and human error. But malfunctioning and inoperable safety systems at the plant meant that its last line of defense failed.

More red alerts

There have been only a few previous examples of hackers using cyberspace to try to disrupt the physical world. They include Stuxnet, which caused hundreds of centrifuges at an Iranian nuclear plant to spin out of control and destroy themselves in 2010, and CrashOverride, which Russian hackers used in 2016 to strike at Ukraine’s power grid. (Our sidebar provides a summary of these and other notable cyber-physical attacks.)

However, not even the most pessimistic of cyber-Cassandras saw malware like Triton coming. “Targeting safety systems just seemed to be off limits morally and really hard to do technically,” explains Joe Slowik, a former information warfare officer in the US Navy, who also works at Dragos.

Other experts were also shocked when they saw news of the killer code. “Even with Stuxnet and other malware, there was never a blatant, flat-out intent to hurt people,” says Bradford Hegrat, a consultant at Accenture who specializes in industrial cybersecurity.

Ariel Davis

It’s almost certainly no coincidence that the malware appeared just as hackers from countries like Russia, Iran, and North Korea stepped up their probing of “critical infrastructure” sectors vital to the smooth running of modern economies, such as oil and gas companies, electrical utilities, and transport networks.

In a speech last year, Dan Coats, the US director of national intelligence, warned that the danger of a crippling cyberattack on critical American infrastructure was growing. He drew a parallel with the increased cyber chatter US intelligence agencies detected among terrorist groups before the World Trade Center attack in 2001. “Here we are nearly two decades later, and I’m here to say the warning lights are blinking red again,” said Coats. “Today, the digital infrastructure that serves this country is literally under attack.”

At first, Triton was widely thought to be the work of Iran, given that it and Saudi Arabia are archenemies. But cyber-whodunnits are rarely straightforward. In a report published last October, FireEye, a cybersecurity firm that was called in at the very beginning of the Triton investigation, fingered a different culprit: Russia.

The hackers behind Triton had tested elements of the code used during the intrusion to make it harder for antivirus programs to detect. FireEye’s researchers found a digital file they had left behind on the petrochemical company’s network, and they were then able to track down other files from the same test bed. These contained several names in Cyrillic characters, as well as an IP address that had been used to launch operations linked to the malware.

That address was registered to the Central Scientific Research Institute of Chemistry and Mechanics in Moscow, a government-owned organization with divisions that focus on critical infrastructure and industrial safety. FireEye also said it had found evidence that pointed to the involvement of a professor at the institute, though it didn’t name the person. Nevertheless, the report noted that FireEye hadn’t found specific evidence proving definitively that the institute had developed Triton.

Researchers are still digging into the malware’s origins, so more theories about who’s behind it may yet emerge. Gutmanis, meanwhile, is keen to help companies learn important lessons from his experience at the Saudi plant. In a presentation at the S4X19 industrial security conference in January, he outlined a number of them. They included the fact that the victim of the Triton attack had ignored multiple antivirus alarms triggered by the malware, and that it had failed to spot some unusual traffic across its networks. Workers at the plant had also left physical keys that control settings on Triconex systems in a position that allowed the machines’ software to be accessed remotely.