Recent Iranian incursions include a suspected effort to sabotage electricity supplies with a thwarted attack on the partner company of a big electricity provider in Britain

They sound harmless enough. But Helix Kitten and Rocket Kitten are among the hybrid warfare weapons being deployed by Iran against Britain and America.

Military strategists have for long been warning about the cyber-warfare threat. Now, as geopolitical tensions intensify, it has become a reality: besides detaining British oil tankers and tourists with British links, Iran launches regular covert raids into Britain’s digital sphere, security sources say.

Iran was identified last week, alongside Russia, as one of the targets of the National Cyber Force, which will bring together intelligence and military hackers for proactive and retaliatory attacks against states threatening the UK.

Security experts warn that, despite plans for the new cyber-warfare agency, Britain is ill-prepared to defend itself against attacks by a shadowy network