I just thought I'd come in here, it's probably the United States, but Kaspersky will never name the nation state behind such an attack, more than they'd dare do. And that's the issue, us mere mortals don't stand a chance. George W. Bush practically admitted to Stuxnet and told Obama to carry on with these cyber attacks. And really we, normal people hit by viruses/ransomware are not on any states priority list, so the Government doesn't care, now nuclear weapons and the possibility of an attack is.