Learn in the textbookMalware Variants and Specialized Types
DefinitionA keylogger (キーロガー) is malware that records the characters typed on a keyboard, in order, and lets the attacker obtain that record.
ExplanationEven input that the screen masks, such as a password, is captured the moment each key is pressed, so it can still be stolen. Countermeasures include on-screen keyboards where you pick characters with the mouse, and one-time passwords that work only once.
Memory hookSplit it into "key" and "logger". A logger keeps a log, and "log" comes from a ship's log book.