Cyber extortion attack hits countries across the world

Dozens of countries were hit with a huge cyber extortion attack Friday that locked up computers and held users' files for ransom at a multitude of hospitals, companies and government agencies. It was believed to the biggest attack of its kind ever recorded. The malicious software behind the onslaught appeared to exploit a vulnerability in Microsoft Windows that was supposedly identified by the National Security Agency for its own intelligence-gathering purposes and was later leaked to the internet. Britain's national health service fell victim, its hospitals forced to close wards and emergency rooms and turn away patients. Russia appeared to be the hardest hit, according to security experts, with the country's Interior Ministry confirming it was struck.