“What gave the Russian hacking, detected more than two years ago, such global reach was its improvised search tool — antivirus software made by a Russian company, Kaspersky Lab, that is used by 400 million people worldwide, including by officials at some two dozen American government agencies.” The software that was supposed to protect the system was being used to hack the system. From the NYT: How Israel Caught Russian Hackers Scouring the World for U.S. Secrets. “It was a case of spies watching spies watching spies.”