Investigators say they believe the same Russian hackers that carried out attacks on the White House and State Department last year and the attempted penetration of the Pentagon last month were responsible for a major cyberattack that shut down the Joint Chiefs of Staff email for the past 11 days, The Daily Beast has learned.
In all of the attacks, hackers broke into unclassified email networks by sending legitimate-looking emails than turned out to be malware or “spear phishing” attempts. In April, President Obama’s unclassified emails were among those compromised, along with the State Department.
Ten days before the July 27 hacking of the Joint Staff system, the Pentagon sent an email warning “at least five” DOD computer users had been targeted, which was first reported by The Daily Beast. The notice linked those attacks to penetrations of unclassified networks at the White House and State Department that began last year.
The Joint Chiefs then suffered what one defense official called the “most sophisticated” attack on its unclassified network, one that has shut down communications ever since for the 4,000 employees on the Joint Staff unclassified server.