What type of security attack involves monitoring network traffic and data without making changes?

• A. Passive
• B. Active
• C. Man-in-the-Middle
• D. Denial of Service

Answer: (A)

Observing traffic without altering it is a passive attack. In this scenario, the attacker listens to communications, captures packets, and analyzes data to learn confidential information, all without changing, injecting, or disrupting the traffic. This preserves the normal operation of the network while compromising confidentiality.

Active attacks, by contrast, involve modifying, injecting, or disrupting traffic, which changes the data flow or service behavior. A man-in-the-middle can be active because it typically intercepts and may alter communications between two parties. Denial of service focuses on degrading or stopping service, not on quietly watching the traffic.