What type of attack is described when an attacker intercepts communications between two entities without their knowledge?

• A. Denial of Service
• B. Replay attack
• C. Man-in-the-middle attack
• D. Social engineering

Answer: (C)

Intercepting communications between two parties without their knowledge describes a man-in-the-middle attack. In this scenario, the attacker positions themselves on the communication path, secretly eavesdropping on the data, and potentially altering messages or impersonating one party to the other. This allows theft of sensitive information, session hijacking, or manipulation of exchanged data without either side realizing it. Denial of Service focuses on making a service unavailable rather than secretly intercepting or altering communications. A replay attack involves capturing valid messages and replaying them later, which is a related but different threat centered on reusing data rather than maintaining an in-between position for ongoing communication. Social engineering targets people rather than the communication channel itself. Defenses include strong end-to-end encryption, proper certificate validation, mutual authentication, and secure network protections like VPNs.