U.S. cybersecurity firm FireEye discloses breach, theft of hacking tools

FILE PHOTO: The FireEye logo is seen outside the company's offices in Milpitas, California, December 29, 2014. REUTERS/Beck Diefenbach

(Reuters) - FireEye, one of the largest cybersecurity companies in the United States, said on Tuesday that it had been hacked, likely by a government, and that an arsenal of hacking tools used to test the defenses of its clients had been stolen.

The hack of FireEye, a company with an array of contracts across the national security space both in the United States and its allies, is among the most significant breaches in recent memory. The company's shares dropped 8% in after-hours trading.