Stuxnet creators recognized they had built the world's first true cyber-weapon and were more interested in pushing the envelope of this new type of digital warfare than causing large-scale destruction within targeted Iranian nuclear facilities, a study shows.
In an analysis released Wednesday, Ralph Langner, head of The Langner Group and a renowned expert in industrial control systems (ICS), also refuted arguments that only a nation-state had the resources to launch a Stuxnet-like attack. Assailants with less ambition could take the lessons learned and apply them to civilian critical infrastructure, he said.
"While Stuxnet was clearly the work of a nation-state – requiring vast resources and considerable intelligence – future attacks on industrial control and other so-called 'cyber-physical' systems may not be," Langner said in an article he wrote about his study for Foreign Policy magazine.
Langner's analysis was based on reverse engineering the attack code in Stuxnet and combining the data with the design of the targeted nuclear facility and background information on the uranium-enrichment process.
Langner concluded that Stuxnet comprised two radically different destructive payloads. The first one, which had been around at least since 2007, was much more complex and was capable of causing catastrophic damage by increasing the pressure within centrifuges used to enrich uranium.
The second payload, which came years later and was much simpler, manipulated rotor speeds, so centrifuges could be damaged enough to force Iranian engineers to replace them, causing continuous delays.
The creators of Stuxnet, which media reports say was a joint project of the U.S. and Israeli governments, decided to use the second version, indicating a major change in strategy.
"The attackers were in a position where they could have broken the victim's neck, but they chose continuous periodical choking instead," Langner said.
"Stuxnet is a low-yield weapon with the overall intention of reducing the lifetime of Iran's centrifuges and making the Iranians' fancy control systems appear beyond their understanding."
Langner estimates that Stuxnet, which was discovered by security researchers in 2010, set back the Iranian nuclear program by two years, about the same amount of time that would have been lost if the attackers had destroyed all operating centrifuges at one time.
Stuxnet creators were also interested in monitoring contractors who worked on the Iranian facilities. The malware exploited previously unknown vulnerabilities in Windows, making it possible for Stuxnet to infect contractors' laptops when they were plugged into the Iranian network. Stuxnet then reported the Internet protocol address and hostnames of infected systems back to command-and-control servers.
Spreading the malware to "soft targets," eventually led to Stuxnet's discovery, Langner said. But by then, the attackers had determined what was possible with cyber-weapons.
Using Stuxnet as a blueprint, attackers would need fewer resources in targeting widely understood ICS in civilian critical infrastructure, such as power plants or water treatment facilities, experts said.
"We need to internalize this new class of threat and defend against it," Andrew Ginter, vice president of industrial security( at Waterfall Security Solutions, said.
Overall, Stuxnet proved that digital weapons are effective without sacrificing lives in combat. They can also be deployed secretly and are "dirt-cheap," Langner said.
"The contents of this Pandora' box have implications much beyond Iran; they have made analog warfare look low-tech, brutal and so 20th century," Langner said.