Interesting revelation. One major red flag associated with this worm was the fact that folks were claiming it got distributed widely via removable media. Turns out that might not be the case…

“As first reported on July 15 by KrebsOnSecurity.com, Stuxnet uses a vulnerability in the way Windows handles shortcut files to spread to new systems. Experts say the worm was designed from the bottom up to attack so-called Supervisory Control and Data Acquisition (SCADA) systems, or those used to manage complex industrial networks, such as systems at power plants and chemical manufacturing facilities.

The worm was originally thought to spread mainly through the use of removable drives, such as USB sticks. But roughly two weeks after news of Stuxnet first surfaced, researchers at Moscow-based Kaspersky Lab discovered that the Stuxnet worm also could spread using an unknown security flaw in the way Windows shares printer resources. Microsoft fixed this vulnerability today, with the release of MS10-061, which is rated critical for Windows XP systems and assigned a lesser ‘important’ threat rating for Windows Vista and Windows 7 computers.”

(Source: ‘Stuxnet’ Worm Far More Sophisticated Than Previously Thought — Krebs on Security)