Susan has attached to her company's network. She has managed to synchronize her boss's sessions with that of the file server. She then intercepted his traffic destined for the server, changed it the w

A sniffing attack involves passively monitoring network traffic, but it does not include actively intercepting, modifying, and injecting altered data, which are key components of the described scenario.

A spoofing attack involves impersonating another entity (e.g., IP spoofing, MAC spoofing), which might be part of establishing a MITM, but the complete described action of interception, modification, and relaying goes beyond just spoofing.

A man-in-the-middle (MITM) attack involves an attacker intercepting communication between two parties, relaying messages between them, and often modifying the messages in transit. The description explicitly states Susan 'intercepted his traffic,' 'changed it,' and 'placed it on the server,' perfectly matching the characteristics of a MITM attack.

A denial of service (DoS) attack aims to make a service or resource unavailable to its legitimate users, which is not what Susan is doing; she is manipulating data, not preventing access.