North Korea plays by its own rules. The isolated, secretive and autocratic country is largely cut off from the world’s economic system – but when it comes to generating foreign earnings it relies on some of the world’s most sophisticated hacking.

Experts, such as TRM Group, quickly attributed the extraordinary $6.3bn (£4.7bn) Binance cryptocurrency theft to TraderTraitor, an elite North Korean hacking unit that has also been known as the Lazarus Group. Though the link may not be proven yet, the pattern of behaviour is familiar.

North Korea has a history of cryptocurrency theft dating back to 2017, focusing on the sector’s relatively lax security controls as a way of stealing money, generating revenues for its military, including…