In a man-in-the-middle (MITM) attack, an attacker intercepts communication between two parties and can read, alter, or inject data without either party knowing. Susan's actions — intercepting and modifying her boss's session data before relaying it to the server — is the classic MITM pattern.

From CEH v13 Official Courseware:

Module 8: Sniffing

Module 11: Session Hijacking

CEH v13 Study Guide states:

“In a MITM attack, the attacker positions themselves between two communicating parties, relaying and possibly altering communications while maintaining the illusion that the parties are communicating directly.”

Incorrect Options:

A: Sniffing only involves passive listening.

B: Spoofing may involve impersonation but not necessarily interception and relay.

D: DoS is about service disruption, not data interception.