It is malicious software that infects the computer device, encrypts its parts and prevents the user from accessing the device and data. As the name reflects, it demands the user to pay money to access the data or to unlock the device by displaying a message on the screen of the device.
There are several levels of ransomware in terms of the different areas it infects or locks in the hard drive. There are several ways to prevent attacks of ransomware.
The users should keep their devices updated in terms of the operating system. An effective antivirus/anti-malware should be used. Users should not open unrecognised websites or software.