APT, usually called as a group or government-like community that has an ability and objective to target an entity persistently.  This concept is utilized to refer to cyber threats especially the internet espionage that uses various intelligence acquisition techniques to access sensitive data. However, it is equally applied to other threats such as traditional espionage or attack. It comprises other acknowledged attack vectors, infected platforms, supply chain accord and social engineering. The aim of these attacks is install malicious codes on one or several computers and stay incognito as much as possible in order to specific missions. Knowledge of tracks of the attacker such as file names helps a network-scope search to recover all affected systems by a professional.

A DDoS attack makes it impossible to stop the attack by blocking a single source effectively as the attack comes from many different sources.