https://www.bleepingcomputer.com/news/security/new-coronavirus-themed-malware-locks-you-out-of-windows/

With school closed due to the Coronavirus pandemic, some kids are creating malware to keep themselves occupied. Such is the case with a variety of new MBRLocker variants being released, including one with a Coronavirus theme.

MBRLockers are programs that replace the 'master boot record' of a computer so that it prevents the operating system from starting and displays a ransom note or other message instead.