APT stands for Advanced Persistent Threat. It refers to a category of cyber attacks that are sophisticated, targeted, and ongoing over an extended period. APT attacks are typically carried out by skilled and well-funded hackers or hacker groups, often sponsored by nation-states or organized criminal organizations. The objective of an APT attack is to gain unauthorized access to a target network or system and maintain a long-term presence to steal sensitive information, gather intelligence, or disrupt operations.