Little by little scientists are beginning to understand Stuxnet a computer worm developed with the sole purpose of doing what sanctions were not able to do, slow down the Iranian march to nuclear weapons. During the past year, Stuxnet the computer worm with a biblical calling card, not only crippled Iran’s nuclear program but has caused a major rethinking of computer security around the globe.
The construction of the worm was so advanced, it was “like the arrival of an F-35 into a World War I battlefield,” says Ralph Langner, the computer expert who was the first to sound the alarm about Stuxnet. Others have called it the first “weaponized” computer virus.
Simply put, Stuxnet is an incredibly advanced, undetectable computer worm that took years to construct and was designed to jump from computer to computer until it found the specific, protected control system that it aimed to destroy: Iran’s nuclear enrichment program.
Stuxnet acted like computer cruise missile rather than a computer virus. The computers it targeted were not connected to the Internet, so it had to be secretly introduced into the Iranian system and hop through a set of unconnected computers, growing and adapting to security measures and other changes until it reached a computer that could bring it into the nuclear facility. And when it reached its target, the worm would have to secretly manipulate the computers running the Iranian nuclear program until its damage was done and then finally it would have to destroy itself without leaving a trace.
That’s exactly what happened both at Natanz, which houses the centrifuges Iran used for processing uranium into nuclear fuel, and at Bushehr, Iran’s nuclear power plant.
At Natanz, for almost 17 months, Stuxnet quietly worked its way into the system and targeted a specific component — the frequency converters made by the German equipment manufacturer Siemens that regulated the speed of the spinning centrifuges used to create nuclear fuel. The worm then took control of the speed at which the centrifuges spun, making them turn so fast in a quick burst that they would be damaged but not destroyed. And at the same time, the worm masked that change in speed from being discovered at the centrifuges’ control panel.
At Bushehr, meanwhile, a second secret set of codes, which Langner called “digital warheads,” targeted the Russian-built power plant’s massive steam turbine.
Here’s how it worked
- The nuclear facility in Iran runs an “air gap” security system, meaning it has no connections to the Web, making it secure from outside penetration. Stuxnet was designed and sent into the area around Iran’s Natanz nuclear power plant — just how may never be known — to infect a number of computers on the assumption that someone working in the plant would take work home on a flash drive, acquire the worm and then bring it back to the plant.
- Once the worm was inside the plant, the next step was to get the computer system there to trust it and allow it into the system. That was accomplished because the worm contained a “digital certificate” stolen from JMicron, a large company in an industrial park in Taiwan. (When the worm was later discovered it quickly replaced the original digital certificate with another certificate, also stolen from another company, Realtek, a few doors down in the same industrial park in Taiwan.)
- Once allowed entry, the worm contained four “Zero Day” elements in its first target, the Windows 7 operating system that controlled the overall operation of the plant. Zero Day elements are rare and extremely valuable vulnerabilities in a computer system that can be exploited only once. Two of the vulnerabilities were known, but the other two had never been discovered. Experts say no hacker would waste Zero Days in that manner.
- After penetrating the Windows 7 operating system, the code then targeted the “frequency converters” that ran the centrifuges. To do that it used specifications from the manufacturers of the converters. One was Vacon, a Finnish Company, and the other Fararo Paya, an Iranian company. What surprises experts at this step is that the Iranian company was so secret that not even the IAEA knew about it.
- The worm also knew that the complex control system that ran the centrifuges was built by Siemens, the German manufacturer, and — remarkably — how that system worked as well and how to mask its activities from it.
- Masking itself from the plant’s security and other systems, the worm then ordered the centrifuges to rotate extremely fast, and then to slow down precipitously. This damaged the converter, the centrifuges and the bearings, and it corrupted the uranium in the tubes. It also left Iranian nuclear engineers wondering what was wrong, as computer checks showed no malfunctions in the operating system
This went on for over a year, the worms causing havoc in the Iranian Nuclear Program. And as it did, the worm grew and adapted throughout the system. As new worms entered the system, they would “get together” with the old ones adapt and become increasingly sophisticated.
And here’s the kicker. You see, Computer Scientists who are analyzing the computer worm that is slowing down Iran’s attempt to develop nuclear weapons may have found a file name that seemingly refers to the Biblical Queen Esther.
Deep inside the computer worm that some specialists suspect is aimed at slowing Iran’s race for a nuclear weapon lies what could be a fleeting reference to the Book of Esther, the Old Testament narrative in which the Jews pre-empt a Persian plot to destroy them.
That use of the word “Myrtus” — which can be read as an allusion to Esther — to name a file inside the code is one of several murky clues that have emerged as computer experts try to trace the origin and purpose of the rogue Stuxnet program, which seeks out a specific kind of command module for industrial equipment.
During this time the worms reported back to two servers that had to be run by intelligence agencies, one in Denmark and one in Malaysia. The servers monitored the worms and were shut down once the worm had infiltrated Natanz. Despite numerous attempts to find those servers, all traces of that communication have disappeared.
Experts, including inspectors from the International Atomic Energy Agency, say that, despite Iran’s claims to the contrary, the worm was successful in its goal: causing confusion among Iran’s nuclear engineers and disabling their nuclear program.
Because of the secrecy surrounding the Iranian program, no one can be certain of the full extent of the damage. But sources inside Iran and elsewhere say that the Iranian centrifuge program has been operating far below its capacity and that the uranium enrichment program had “stagnated” during the time the worm penetrated the underground facility. Only 4,000 of the 9,000 centrifuges Iran was known to have were put into use. Some suspect that is because of the critical need to replace ones that were damaged.
Whoever developed this worm is doing great work. Now if they can only develop a computer worm to target the WikiLeaks computer.