Learn in the textbookTargeted Attacks and Phishing Scams
DefinitionAPT (Advanced Persistent Threat) is a targeted attack that keeps going over a long period against a specific organization or person, combining several methods.
ExplanationIt does not stop after one break-in: it lies low inside the organization, widens what it controls little by little, and may keep carrying off confidential information for months. Because it moves quietly, defenses must watch for suspicious outbound traffic as well as block intrusion. The model that shows an attack advancing in stages from reconnaissance to achieving its goal is called the cyber kill chain (サイバーキルチェーン).
AnalogyIt is less like a thief who grabs everything in one night and flees, and more like a spy who moves in posing as a housemate and slips valuables out bit by bit over a long time.
Memory hookOf the three letters, P (Persistent: keeps at it) is what sets it apart from other targeted attacks.