What's ransomware virus and should be worried? Everything you should know Reuters | Whats-ransomware-virus-and-should-be-worried-Everything-you-should-know Malicious software called 'ransomware' has forced British hospitals to turn away patients and affected Spanish companies such as Telefonica as part of a global outbreak that has affected tens of thousands of computers. HOW DOES IT WORK? WannaCry is a form of "ransomware" that locks up the files on your computer and encrypts them in a way that you cannot access them anymore. HOW DOES IT SPREAD? Ransomware is a program that gets into your computer, either by clicking on the wrong thing or downloading the wrong thing, and then it holds something you need to ransom. In the case of WannaCry, the program encrypts your files and demands payment in bitcoin in order to regain access. Security experts warn there is no guarantee that access will be granted after payment. Some ransomware that encrypts files ups the stakes after a few days, demanding more money and threatening to delete files altogether.