Motion designer Patrick Clair tells the story of Stuxnet, "a Microsoft Windows computer worm discovered in July 2010 that targets industrial software and equipment."
This great video explain what is considered the first digital weapon of mass destruction.
Stuxnet can stay dormant and undetectable until needed and can increase pressure in nuclear reactors and turn off oil pipelines, all the while showing monitors everything is fine.
More incredible though it is open source and in parts downloadable on line.
Stuxnet: Anatomy of a Computer Virus from Patrick Clair on Vimeo.