The scenario describes a classic Denial-of-Service (DoS) attack. The objective of a DoS attack is to make a computer or network resource unavailable to its legitimate users by overwhelming it with a flood of traffic or malicious requests. The use of "several computers" indicates a Distributed Denial-of-Service (DDoS) attack, a common and powerful form of DoS. The malicious hacker coordinates these compromised machines (a botnet) to collectively send high volumes of data, exhausting the target's resources (e.g., bandwidth, CPU, memory) and preventing it from serving legitimate requests.

A. Zero-day exploit: This is an attack that leverages a previously unknown vulnerability in software. The scenario describes a traffic flood, not the exploitation of a specific software flaw.

B. Ransomware: This is a type of malicious software that encrypts a victim's data and demands a ransom for its release. The attack described does not involve data encryption.

D. Worm: This is a standalone malware program that replicates itself to spread to other computers. While a worm could be used to create the botnet, the attack itself is DoS.

1. National Institute of Standards and Technology (NIST). (2012). Computer Security Incident Handling Guide (NIST Special Publication 800-61 Rev. 2). Section 2.3.3, "Denial of Service," p. 2-6. The document defines a DoS attack as "an action that prevents or impairs the authorized use of networks, systems, or applications by exhausting resources such as central processing units (CPU), memory, bandwidth, and disk space."

2. Kurose, J. F., & Ross, K. W. (2017). Computer Networking: A Top-Down Approach (7th ed.). Pearson. Chapter 8.2, "Principles of Secure Networking," discusses Denial-of-Service attacks, describing them as attacks that render a network, host, or other piece of infrastructure unusable by legitimate users by flooding the resource with bogus traffic.

3. Saltzer, J. H., & Kaashoek, M. F. (2009). Principles of Computer System Design: An Introduction. MIT OpenCourseWare. Chapter 11, "Security and Protection," Section 11.6.2, "Denial of Service," p. 438. This text explains that DoS attacks aim to "prevent legitimate users from getting service" by consuming a critical, non-shareable resource.