Ex-GCHQ chief: No company should be offline for weeks after cyberattackRobert Hannigan said no company hit by a cyberattack should be offline for two weeks (Photo by Ben Birchall/AFP via Getty Images)No vigilant company should need to go offline for more than a few days after a cyberattack, the former director of GCHQ has said in comments that will pile fresh scrutiny on Jaguar Land Rover’s (JLR) preparedness before its hack left production at a standstill for over a month. “It is perfectly possible to build the right prevention defences and then build the right resilience,” he said. Read more Asahi cyberattack halts domestic operations amid ongoing investigationThe Tata-owned company said on Monday that it hoped to partially restart operations “within days”. But Hannigan said there was “absolutely no need for a major company to be taken offline for weeks or months” in the way JLR has been. And M&S was forced to announce a £300m write-down after a devastating cyberattack disrupted its services for weeks.