Stuxnet is a computer worm that can do as much damage as a bomb could in destroying an industrial plant or military installation. The Wikipedia entry about Stuxnet says it is the first discovered worm that spies on and reprograms industrial systems.
Stuxnet's capabilities are clear following its use to attack Iran's nuclear installations. The implications are considerable. Any enterprise that uses industrial control systems could be attacked by the worm, potentially causing as much damage as any sort of explosion.
Iran states the attack did not affect its nuclear program. But experts say it's possible that the worm is the reason why Iran delayed the start of its uranium enrichment program.
The Jerusalem Post interviewed a German security expert who said Stuxnet contained two digital warheads, each with its own purpose.
Expert Ralph Langner said the first digital warhead attacked Iran's centrifuge facilities. These buildings are used to enrich uranium. This digital warhead had the ability to discover and attack centrifuge facilities that inspectors would never know about.
The second digital warhead was distinctly different. It had the purpose of attacking the Busherer nuclear power plant in Iran. Bushehr is the first nuclear power plant to be built in the Middle East. It is due to be completed in the near future.
This part of the code attacked the external turbines of the plant. It had the ability to "destroy the turbine as effectively as an air strike."
The implications of these attacks shows how industrial systems can be compromised. Smart attacks can affect an industrial plant as much as it can a military installation. By any measure, that makes Stuxnet a game changer with long term impacts on how we protect our most critical assets.