The W32.Stuxnet worm has raised quite much discussion as its been analysed and technical details about its construction has been revealed. Stuxnet is special because it’s very complex and its targeted to attack very specific set of industrial process computers. These and other worm characteristics hints that the worm was created by a government  sponsored virus laboratory.

Some notable Stuxnet features include:

• Four zero day exploits to windows operating system.
• Stolen driver authentication certificates, including two from Realtek
• Targeted to specific installation – it didn’t infect if it found to be in wrong computer.
• Very installation specific payload which altered the process of the industrial control operations.

The following quote from [http://langner.com/en/] sums up all this pretty well:

The attack combines an awful lot of skills — just think about the multiple 0day vulnerabilities, the stolen certificates etc. This was assembled by a highly qualified team of experts, involving some with specific control system expertise. This is not some hacker sitting in the basement of his parents house. To me, it seems that the resources needed to stage this attack point to a nation state.

Read the full analysis paper at http://www.eset.com/resources/white-papers/Stuxnet_Under_the_Microscope.pdf

Also read the symantec blog at http://www.symantec.com/connect/blogs/exploring-stuxnet-s-plc-infection-process