Ukraine’s national bank, state power company, and largest airport are among the targets of a huge cyber attack on government infrastructure. Rozenko Pavlo, the deputy Prime Minister, said he and other members of the cabinet were unable to access their computers. He tweeted an image of his PC displaying a message claiming a disk “contains errors and needs to be prepared”, urging the user not to turn it off.

Images from other affected computers showed what appeared to be ransomware, demanding a payment of $300 (£235) in Bitcoin to re-gain access to encrypted files. Ukrainian state-run aircraft manufacturer Antonov was among the companies hit, along with state power distributor Ukrenergo, which said the attack did not affect power supplies. READ MORE