Ransom is a type of malware that denies access to a computer or its data and requires a ransom (money for release).
How does a ransom program work?
When a computer is infected with a ransom demand, it connects to a server to activate itself, then begins encrypting data from the infected computer and sends it to the server. Once all files have been encrypted, a message will appear on your computer asking you to pay for the decryption of the files – and threatening to delete the data if it is not paid. In most cases, a timer is used to increase the urgency.
How is the ransom software distributed?
Most ransom software is distributed by hiding it in email attachments such as Word documents, PDFs and other files. Another option is malware networks installed on computers that are already infected with viruses, providing a back door for further attacks.