As well as forcing the NHS to cancel operations and shut some services, production at Renault and Nissan factories was stopped, computer systems at O2’s owner Telefonica were hit and FedEx’s logistics operations were affected.

 

Mr Martin said the NSC’s investigation into who was responsible were ongoing and warned businesses to “expect further significant incidents”.

 

Security analysts have criticised large companies for a lack of boardroom responsibility for IT safeguards, claiming this makes the type of attacks that have hit TalkTalk and Tesco Bank more likely.

 

Many corporate computer systems continue to run outdated software without the latest security updates, making them vulnerable to hackers.

 

Source