In Januaryinspectors with the International Atomic Energy Agency noticed that centrifuges at an Iranian uranium enrichment plant were failing at an unprecedented rate.
The cause was a complete mystery—apparently as much to the technicians replacing the centrifuges as to the inspectors observing them. Then, five months later, a seemingly unrelated event occurred: A computer security firm in Belarus was called in to troubleshoot some computers in Iran that were crashing and rebooting repeatedly.
But as they and other experts around the world investigated, they discovered a mysterious virus of unparalleled complexity.
For Stuxnet, as it came to be known, was unlike any other virus or worm built before: Rather than simply hijacking targeted computers or stealing information from them, it escaped the digital realm to wreak actual, physical destruction on a nuclear facility. But Countdown to Zero Day ranges far beyond Stuxnet itself. Here, Zetter shows us how digital warfare developed in the US. She reveals just how vulnerable many of our own critical systems are to Stuxnet-like strikes, from nation-state adversaries and anonymous hackers alike—and shows us just what might happen should our infrastructure be targeted by such an attack.