Which term describes a security threat where the attacker sits between two communicating endpoints to intercept or alter messages?

• A. Man-in-the-Middle (MitM)
• B. Masquerading
• C. MAC Address
• D. Multicast

Answer: (A)

Interception and possible modification of messages by placing the attacker between two communicating endpoints is called a Man-in-the-Middle attack. In this scenario, the attacker interposes themselves in the communication path so that data from one side goes through the attacker before reaching the other side. This positioning lets the attacker eavesdrop on sensitive information, alter messages, or impersonate either party, potentially compromising confidentiality, integrity, and authentication. The term Man-in-the-Middle highlights both the middle-in-the-path placement and the tampering ability, which matches the threat described.

Masquerading involves pretending to be someone else, which is about impersonation rather than actively intercepting traffic between two endpoints. A MAC address is just a hardware identifier and not a security threat by itself. Multicast refers to delivering data to multiple recipients, not to a security attack.