The computer systems of the agency in charge of America’s nuclear weapons stockpile are “under constant attack” and face millions of hacking attempts daily, according to officials at the National Nuclear Security Administration. Thomas D’Agostino, head of the agency, says the agency faces cyber attacks from a “full spectrum” of hackers. “They’re from other countries’ [governments], but we also get fairly sophisticated non-state actors as well,” he said. “The [nuclear] labs are under constant attack, the Department of Energy is under constant attack.” A spokesman for the agency says the Nuclear Security Enterprise experiences up to 10 million “security significant cyber security events” each day. “Of the security significant events, less than one hundredth of a percent can be categorized as successful attacks against the Nuclear Security Enterprise computing infrastructure,” the spokesman said—which puts the maximum number at about 1,000 daily.