Russian government hackers stole highly classified information from the National Security Agency, detailing how the U.S. defends against cyberattacks and penetrates the computer networks of foreign nations, the Wall Street Journal reported Thursday. The information was reportedly stolen after an NSA contractor put the material on his home computer, which was targeted by the contractor’s use of a widely used antivirus software made by Russia-based Kaspersky Lab. The federal government had previously warned its agencies against buying from the company due to cyber-espionage concerns. Experts reportedly consider the theft to be the most significant security breach in recent years.
