Russia launched a "sophisticated cyber attack" on the Pentagon’s unclassified email system used by the Joint Chiefs of Staff.
NBC News reported that Russian sources were responsible for the "sophisticated cyber intrusion," which was carried out around July 25. The Pentagon took the unclassified system offline about two weeks ago, citing suspicious activity.
The hack affected approximately 4,000 military and civilian employees of the Joint Chiefs of Staff who use the system, including Chairman Gen. Martin Dempsey.
A defense official to the Daily Beast that the cyberattack involved "new and unseen approaches into the network" and was the "most sophisticated" attack of its kind in military history. Officials are investigating if a "state entity" was involved.
In recent weeks, two high-ranking Pentagon generals tapped by President Obama to hold top posts in the Joint Chiefs of Staff have named Russia as the most significant existential threat to the United States.
U.S. Air Force Gen. Paul Selva, nominated by Obama to serve as the next vice chairman of the Joint Chiefs of Staff, in remarks to the Senate Committee on Armed Services last month labeled Russia, China, and Iran the top three countries posing threats to the United States.
He joined Marine Corps Gen. Joseph Dunford, Obama’s choice to serve as the next chairman of the Joint Chiefs, in highlighting Russia as the most significant threat to the United States.
"If you want to talk about a nation that could pose an existential threat to the United States, I’d have to point to Russia," Dunford said during his own confirmation hearing before the Armed Services Committee, focusing on Putin’s actions in Ukraine. "If you look at their behavior, it’s nothing short of alarming."