- Ransomware is a subset of malware in which the data on a victim's computer is locked -- typically by encryption -- and payment is demanded before the ransomed data is decrypted and access is returned to the victim. The motive for ransomware attacks is usually monetary, and unlike other types of attacks, the victim is usually notified that an exploit has occurred and is given instructions for how to recover from the attack. Payment is often demanded in a virtual currency, such as bitcoin, so that the cybercriminal's identity is not known.

- Ransomware malware can be spread through malicious attachments found in emails or in infected malicious software apps, infected external storage devices and compromised websites. Attacks have also used Remote Desktop Protocol and other approaches that do not rely on any form of user interaction.