The US and Israel jointly developed the infamous Stuxnet worm before using the sophisticated malware to sabotage key components of Iran's controversial nuclear program, according to an investigation by the New York Times.
Stuxnet selectively infects industrial control (SCADA) systems from Siemens, establishing a backdoor that creates a means to reprogram compromised systems. The worm initially spread using a battery of four zero-day Windows vulnerabilities before using insecure network shares and USB sticks to spread across networks. Windows machines can carry the infection but malware only comes into play if infected systems are used to operate certain industrial control systems.
The malware is finely tuned so that it can alter the speed of high-speed frequency converter drives, such as those used in uranium enrichment, as explained in a blog post by Symantec here. It doesn't do anything for mainstream industrial control set-ups, even after they are connected to industrial control systems.
Stuxnet began spreading in June 2009 but its sophistication, including elaborate steps to disguise its presence on infected systems, meant it was not detected until June 2010. The malware infected hundreds of thousands of systems, with most infections appearing in Iran and Indonesia.
After months of confusing and occasionally conflicting statements, Iranian president Mahmoud Ahmadinejad recently confirmed that the worm had sabotaged uranium-enrichment centrifuges at Natanz. Production at the facility reportedly dropped by 30 per cent, setting Iran's nuclear programme back by months as a result.
The consensus among anti-virus analysts, who have spent months poring over the details of the 1.5MB malware code, was that the malware would have taken weeks to develop by a skilled team – with access to industrial control systems, for testing.
The absence of any clear financial motive, and the obvious time and trouble needed to develop the malware, point to the likely involvement of a state-sponsored intelligence agency.
Either Israel or the US have long been fingered as the most likely suspects in creating the worm. The New York Times investigation fleshes out this theory, a little, by saying both Israel and the US created the worm.
Unnamed sources at Israel's Dimona Complex said the malware was developed there over the last two years as part of a joint US-Israeli operation designed to sabotage Iran's nuclear programme. The foundations of this work were reportedly laid by American intelligence agencies, who identified the type of controllers Iran intended to use and their vulnerabilities back in 2008. Testing of the Siemens controllers took place at the Idaho National Laboratory as part of a larger exercise in cybersecurity testing, according to the sources.
The NYT story doesn't explain how the malware was delivered, though it has been previously speculatively suggested that the malware was introduced by Russian sub-contractors at the Bushehr Nuclear Power Plan, either accidentally or deliberately.
While fleshing out the Mossad-created-Stuxnet theory somewhat, the NYT piece is unlikely to convince anyone who disagrees with this version of events. Alternative explanations exist, such as one theory that the malware originated in China. ®