Which of the following actions does not affect system resources in a passive attack?

• A. Unauthorized data access
• B. Information gathering without interference
• C. System performance monitoring
• D. Service interruption

Answer: (B)

The action that does not affect system resources in a passive attack is information gathering without interference. In a passive attack, the attacker typically observes and gathers information from the network or system without altering or disrupting any processes. This means that the system resources remain unaffected, as the collecting of data does not engage with the system in a way that consumes its resources or alters its performance.

In contrast, actions like unauthorized data access, system performance monitoring, and service interruption all have an active component or involve an interaction that can drain system resources or alter their availability. For instance, unauthorized data access typically requires direct engagement with the system to retrieve information, which impacts resources. Similarly, monitoring system performance involves collecting data which can slow down or otherwise affect the system's operation. Finally, service interruption directly affects resource availability by disrupting the normal functioning of the system. Hence, the nature of passive attacks keeps the system intact, focusing solely on surveillance without engagement.