In 2010, computer security researchers discovered a mysterious virus/worm infecting computers in Iran. At first, they believed the malicious code was a simple, routine piece of malware. But as they and other experts around the world dug into the code, they found that it was a virus of unparalleled sophistication and complexity. They had, they soon learned, stumbled upon the world's first digital weapon. Stuxnet, as it came to be known, was unlike other viruses and worms built before because rather than simply hijacking targeted computers or stealing information from them, it escaped the digital realm to physically destroy equipment the computers controlled. Stuxnet had been designed and launched to destroy centrifuges used in a uranium-enrichment plant in Iran in order to set back the Islamic Republic's nuclear program and prevent it from producing a nuclear weapon.