Beware the rise of state-sponsored cyberattacks

In November 2014, a glowing red skeleton appeared on the computer screens of executives at Sony Pictures Entertainment. ‘Hacked,’ began the accompanying message. It went on to explain that Sony data had been stolen and would be released to the world. ‘This is only the beginning,’ it warned. Gossipy emails about Angelina Jolie, licensing problems around the character of Spider-Man, and the script of the next James Bond film were all leaked online and lapped up by showbusiness reporters.

Then things became much more serious. The hackers threatened a terror attack against the premiere of Seth Rogen’s film The Interview, which mocked North Korea and its leader. The studio capitulated, the premiere was cancelled and the film was never given a major cinematic release.

Two and a half years later, computers in hospitals all around Britain displayed a ransom demand: pay us $300 (£220) in Bitcoin or your files will be lost.