FireEye, a Top Cybersecurity Firm, Says It Was Hacked by a Nation-State. The Silicon Valley company said hackers — almost certainly Russian — made off with tools that could be used to mount new attacks around the world. FireEye revealed on Tuesday that its own systems were pierced by what it called “a nation with top-tier offensive capabilities.” The company said hackers used “novel techniques” to make off with its own tool kit, which could be useful in mounting new attacks around the world.