The Stuxnet worm is a "groundbreaking" piece of malware so devious in its use of unpatched vulnerabilities and so sophisticated in its multipronged approach that the security researchers who tore it apart believe it may be the work of state-backed professionals.

"It's amazing, really, the resources that went into this worm," said Liam O' Murchu, manager of operations with Symantec's security response team. "I'd call it groundbreaking," said Roel Schouwenberg, a senior antivirus researcher at Kaspersky Lab.