Advanced Persistent Threat (APT) is a term describing a sophisticated and prolonged cyber attack in which professional attackers such as ransomware gangs or nation state actors carry out sustained attacks on a system or organization with specific objectives.

APT attacks are characterized by the significant investment of time, resources, and expertise, and are usually aimed at achieving high-value targets such as the theft of sensitive information, industrial espionage, or ransomware and extortion.

Known APT groups and their TTPs can be found the MITRE ATT&CK.