Images appeared on victims' screens demanding payment of $300 in Bitcoin
Malicious software called 'ransomware' has forced British hospitals to turn away patients
Russian health ministry aide said that the ministry had 'quickly thwarted' the attempted attacks
Rudd said the attack was not specifically targeted at Britain's health service
Russia worst hit, followed by Ukraine, India and Taiwan, say experts
Nearly hundred countries, including India, have been hit by a massive cyber-attack
Here are ways to prevent not only Wannacry/ WannaCrypt Ransomware, but also any other cyber attack
One crucial element that has been missing from American cybersecurity efforts is cyber-deterrence