Malware
CoViper
PCRisk notes that CoViper is yet another Coronavirus/COVID-19-themed malware infection, most likely proliferated as a file related to the pandemic.
CoViper is a Windows malware family.
Background
PCRisk identifies CoViper as one more Coronavirus/COVID-19-themed infection, likely distributed under the guise of a pandemic-related file. Its mechanism is to overwrite the system's Master Boot Record (MBR): rather than erasing the original, it backs it up and substitutes a custom MBR in its place. MBR-altering malware generally does this to stop the operating system from booting, and CoViper further presents a full-screen message, frequently a ransom note, which locks the user out of the device.
Source: Malpedia (Fraunhofer FKIE).