Which of the following are types of social engineering attacks? Each correct answer represents a complete solution. Choose two.

Impersonating a system administrator over the phone to extract credentials or access is a classic social engineering technique known as pretexting, which exploits human trust rather than technical weaknesses.

Inserting intermediary software between two communicating parties describes a man-in-the-middle attack, which is a technical network-based attack, not a social engineering attack.

Modifying packet headers using someone else's IP address describes IP spoofing, which is a technical attack exploiting network protocols, not a manipulation of human behavior.

An unauthorized person physically entering a secured building by exploiting human courtesy or following authorized personnel - known as tailgating or piggybacking - is a social engineering attack that targets people and physical security controls rather than systems.