Learn in the textbookMalware Basics and Major Infection Types
DefinitionRansomware (ランサムウェア) is malware that makes files or a PC unusable by encrypting the files or locking the PC, then demands money (a ransom) in exchange for restoring them.
ExplanationThe attacker's main goal is to hold the locked-up data hostage and collect money. Paying the demand does not guarantee recovery, so the way to prepare is to take regular backups (バックアップ) and keep them somewhere an infected PC cannot overwrite.
AnalogyIt is like someone changing every lock in your house without asking and then saying, “Pay up if you want the keys.”
Memory hookRansom is English for the money paid to free a hostage. Ransom + software gives ransomware.