Which of the following BEST describes malicious software that demands the end-user pay a fee or face the destruction of their files?

A Trojan (Trojan horse) is a type of malware that disguises itself as legitimate software but carries out malicious activities, without primarily focusing on demanding a ransom.

A virus is a type of malware that attaches itself to legitimate programs and replicates itself, spreading to other computers, but its primary characteristic is not demanding a ransom.

Spyware is software that secretly gathers information about a user and sends it to another party, without explicitly demanding payment for file access.

Ransomware is a specific type of malicious software that encrypts a victim's data or locks their computer, preventing access until a ransom payment is made, often with a threat of data destruction if the payment deadline is missed. This directly matches the description of demanding a fee or facing file destruction.