New reports paint the source of the leak as an actual NSA employee, not a contractor, as was originally reported by The Wall Street Journal. The employee loaded classified NSA files onto his home computer that in turn was hacked by Russian cyber spies in 2015. The new tools were among the files pilfered by Russian nation-state hackers. The breach wasn’t detected until the spring of 2016, and wasn’t known publicly until the WSJ report. Security experts say the reports raise more questions than answers about how the attack actually occurred.”]
Source: https://www.darkreading.com/attacks-breaches/russian-hackers-targeted-nsa-employee-s-home-computer