And it has been claimed that they have stolen more than $1 billion in an international crime spree. They are the Lazarus Group, a shadowy cabal of hackers accused of working on behalf of the North Korean state. North Korea denies the allegations, sayingthe accusations are American attempts to tarnish its image.From the streets of Dhaka to the casinos of Macau to the secretive capital of Pyongyang, this shocking story uncovers the secret world of the Lazarus Group, their victims and those who have tried - and so far failed - to stop them.