Which of the following describes a Denial of Service attack?

A Denial of Service (DoS) attack is fundamentally designed to disrupt the normal functioning of a targeted server, service, or network. This is achieved by overwhelming the system with a flood of traffic or by exploiting specific vulnerabilities that cause the service to become unavailable to legitimate users. The primary goal of a DoS attack is to deny users access to the resources or services they need, which can result in significant downtime and impact on operations.

Understanding DoS attacks is crucial for anyone involved in cybersecurity, especially in contexts like marine safety, where consistent access to systems and data is vital for operational success and safety management. While other options mention tactics related to cybersecurity, they do not accurately reflect the core objective of a denial of service attack, which centers on making systems inaccessible rather than stealing credentials, spreading malware, or phishing.