UI is the point when interactions between machines and people happen. It lays down the parameters of a user's interaction with a machine.
Ransomware
Ransomware is a type of malware (malicious software) that has the final goal of convincing victims to pay for a decryption ransom in order to recover their compromised files or system. The payments are normally asked in digital currencies that are difficult to be traced, such as Bitcoin, Monero, or any other cryptocurrency.