For thieves to break into a secure facility, they'd first collect intelligence and build a set of tools to aid them. These tools are expensive, with years of research have gone into them. They'd also need to remain covert, or the operation could be compromised.
However, covertness can get in the way. Do you wait for a perfect date three years from now when a building is being renovated, or carry on to meet your operational goals when a cleaning crew might be in the building?
The same parameters apply with cyberattacks. From a technological standpoint, Stuxnet is very advanced and costly. It uses four vulnerabilities that hadn't been seen before to exploit computer systems for access. One of these enables an attacker to infect a computer by merely inserting a USB key.
This is perfect for attacking a nuclear facility, which isn't connected to the Internet. But operationally it means a person would have to be there physically to accomplish the mission: a spy, a rogue employee, or a commando team.
For such an operation, Stuxnet must not fail. There has to be clear intelligence about how the systems it attacks are built. Also, given the nature of these systems (industrial software that controls power plants, like SCADA systems), it would have to be developed in a replication of the target environment -- an immense cost to reconstruct and an effort in intelligence collection.
Such a tool would be used carefully to avoid the risk of discovery -- not just the specific operation, but of methods used, the technology developed, and past targets.
How then could a target-specific weapon such as Stuxnet be found in tens of thousands of computers worldwide, as vendors such as Microsoft report? It makes no operational sense to attack random computers, which would increase the likeliness of discovery and compromise the operation. Could this be a mistake? Unlikely, as a tool developed for such a specific job would not do anything other than it is told.
Why does Stuxnet infect computers randomly after it gains access to its target? Whatever it is looking for (perhaps a way to phone home?) should already be preplanned.
Further, Stuxnet remained active when, in 2009, one of the zero-day vulnerabilities was reported publicly and patched by Microsoft. Why would its operators risk the discovery of such a costly weapon by keeping it in the field when discovery is now a real risk?
And last but not least, who would have wanted to attack systems in, to name three target countries, Iran, the United States, and Germany, where, according to security vendors, many of the thousands of infections were discovered?
We simply can't tell from technical data alone who is behind it. We can, however, ask what damage has been done and who stood to gain from it.
If we are to believe media reports, then Iran's nuclear efforts have been delayed by three months. These reports are unsubstantiated, but taking them on their word, it doesn't seem likely that Israel or the United States would invest so much for such a small return. It is still within the realm of possibility that some nation-state was behind it, even Iran itself. While in democracies it's the exact opposite, in dictatorial countries most of the intelligence efforts are turned inward.
Another option is that this was a corporate rival of Siemens, the vendor whose SCADA systems Stuxnet targets. Siemens reported it has so far discovered 14 clients (read: power plants) that have been infected, a large portion of which are in Germany. Siemens suffered major PR damage as a result of Stuxnet.
It could also be criminals, with a goal as simple as ransoming these power plants. As unlikely as this scenario sounds, it is as sound a guess as any of the others.
Among the many guesses as to who built Stuxnet, fingers were also pointed at Israel. As an Israeli, I hope such sloppy work wasn't ours. Yes, Stuxnet is advanced, but no military or intelligence organization should be this careless. It is just too amateurish from an operational standpoint.
The plain truth is we don't know who is behind Stuxnet, and we, as experts, shouldn't be ashamed to admit that rather than making outlandish claims that create news. But whoever it was, they were clearly not experienced, even if they were well-funded.
Follow Gadi Evron on Twitter: http://twitter.com/gadievron.
Gadi Evron is an independent security strategist based in Israel. Special to Dark Reading.