Russian hackers broke into the White House computer system, U.S. officials say. The hackers had access to sensitive information such as real-time non-public details of the president’s schedule. The White House in October said it noticed suspicious activity in the unclassified network that serves the executive office. The intrusion was routed through computers around the world, as hackers often do to hide their tracks, but investigators found tell-tale codes and other markers that they believe point to hackers working for the Russian government. Neither the State Department nor the Russian Embassy responded to a request for comment.”]
Source: https://edition.cnn.com/2015/04/07/politics/how-russians-hacked-the-wh/

