U.S. Department of Defense & Strategic Studies Institute 
International Conflicts in Cyberspace — Battlefield of the 21st Century [EPUB ebook] 
Cyber Attacks at State Level, Legislation of Cyber Conflicts, Opposite Views by Different Countries on Cyber Security Control & Report on the Latest Case of Russian Hacking of Government Sectors

Conflict in cyberspace is not a new phenomenon, but the legality of hostile cyber activity at a state level remains imperfectly defined. While the United States and its allies are in general agreement on the legal status of conflict in cyberspace, China, Russia, and a number of like-minded nations have an entirely different concept of the applicability of international law to cyberspace. This e-book presents the opposed views of USA and Russia on cyber security. Ultimately, you can find out from the official report how cyber-attack can jeopardize national security in the latest attack performed by the Russian hackers in order to interfere with the 2016 U.S. elections.