Ann, a customer, is reporting that several important files are missing from her workstation. She recently received communication from an unknown party who is requesting funds to restore the files…

Ransomware is a type of malicious software that encrypts a victim's files, making them inaccessible, and then demands a payment, or 'ransom,' to restore access to the data, typically by providing a decryption key. The scenario directly describes files being held hostage with a demand for funds to restore them, which is the defining characteristic of a ransomware attack.

A keylogger is designed to record keystrokes made on a keyboard, not to encrypt files or demand a ransom for their restoration.

A buffer overflow is a type of software vulnerability where a program attempts to write data beyond the boundaries of a fixed-size buffer, often leading to system crashes or arbitrary code execution, but not directly to file encryption for ransom.

A rootkit is a collection of software tools designed to enable persistent, surreptitious access to a computer while actively hiding its presence and that of other malware, rather than directly encrypting user files and demanding payment.