Stuxnet virus triggers an international whodunit

Intrigue and speculation permeate the story of the computer worm that targeted Iran's nuclear program.

Compared with last summer’s busted Russian spy ring, which was mocked for using buggy software and not-so-secret wireless networks, the spooks presumably behind the ambitious and meticulously crafted Stuxnet computer worm appear to have restored some professional credibility to the field.

That is, if a state-sponsored group was indeed behind the virus, which targets and seeks to reprogram a certain kind of control system used in oil pipelines, electrical power grids and nuclear power plants.

Like any tale of international intrigue worth its salt, the ongoing story is long on speculation about responsible parties, motives and methods and short on well-established facts. As the country with the greatest number of infected computers, Iran appears to be the target of the virus, though many other countries have also been affected, according to security firm Symantec.

Numerous observers think Stuxnet is the handiwork of Israel, which feels threatened by Iran's efforts to develop nuclear weapons. One of the more interesting pieces of information supporting that possibility was the discovery that a file used in the worm is named Myrtus, a reference to the Old Testament’s Book of Esther in which the Jews pre-empt a Persian plot to destroy them, report John Markoff and David Sanger in the New York Times.

Another clue in the code refers to May 9, 1979, the day in which a Persian Jew was executed in Tehran, prompting a mass exodus of Jews from Iran, reports Kim Zetter in Wired.

Others speculate that the United States, also an opponent of Iran’s nuclear ambitions and presumed dabbler in offensive cyber capabilities, could be behind the computer malware. Whoever it was, the worm’s bar-raising sophistication leads many to theorize that it had to be the work of a state-sponsored group, though that assertion can’t be proven unless someone fesses up.

What observers do agree on is that the Stuxnet creators applied unprecedented effort, which Gregg Keizer details in Computerworld. That work included:

  • Taking advantage of four vulnerabilities in Microsoft Windows to gain access to target networks — most malware uses only one vulnerability — and three other unpatched Windows bugs to allow the attack to jump from Windows systems to the industrial control equipment made by Siemens.
  • Obtaining two signed digital certificates to make the software appear legitimate.
  • Replacing an earlier, more stealthy version of Stuxnet that might not have achieved its objectives with subsequent versions that were able to spread to more systems.
  • Identifying and then getting the exact type of Siemens equipment used by the target so the hackers could write and test code that would reprogram the control systems with new instructions designed for mischief.

On that last point, Zetter reports that consequences could include physical destruction of affected systems, such as the explosion of equipment under high pressure.

Given that kind of scenario, Iranian officials were understandably perturbed when they said the virus had infected computers across the country, though they denied that it is causing delays in the opening of their first nuclear power plant at Bushehr, reports William Yong for the New York Times.