Major cyber attacks strike worldwide

A fast-moving wave of cyberattacks swept the globe Friday, apparently exploiting a flaw exposed in documents leaked from the US National Security Agency. The attacks came in the form of ransomware, a technique used by hackers that locks users' files unless they pay the attackers a designated sum in the virtual currency Bitcoin. The scope of the attacks was not immediately clear, but some analysts reported that dozens of countries had been affected, with the malware linked to attacks on hospitals in Britain as well as the Spanish telecom giant Telefonica and the US delivery firm FedEx.