Which attack listens to network traffic of a computer resource?

Eavesdropping is the correct answer because it directly refers to the act of intercepting and monitoring network traffic without the knowledge of the parties involved in the communication. This can be done through various methods, often involving packet sniffing tools, which analyze data packets as they travel through the network. Eavesdroppers can capture sensitive information such as login credentials, personal data, or any other kind of communications that are not encrypted.

In contrast, resource gathering typically refers to the compilation of information about a system or network for purposes of planning an attack, but it does not focus specifically on listening to network traffic. Denial of service attacks aim to overwhelm a resource, making it unavailable to legitimate users, and do not involve intercepting traffic. ARP poisoning, while it can facilitate eavesdropping by redirecting network traffic through a malicious device, is more about manipulating the Address Resolution Protocol to perform attacks rather than listening to traffic itself. Thus, the specific action of listening to network traffic clearly aligns with the definition of eavesdropping.