Cyberwarfare and the truth about the American election hacks

In a world in which almost everything is connected, our society is more target rich for hackers than ever before. It's not surprising, then, that cyber threats now pose a bigger danger to world security than terrorism and nuclear weapons. The New York Times' National Security correspondent David E. Sanger - calls them 'The Perfect Weapon', the title of his new book. He talks to Kathryn Ryan about his investigations and how cyber warfare is transforming geo-politics; from the US attacks on Iran and North Korea, to the Russian attacks on the American election, and the wanna cry hack that temporarily crippled the NHS.