Which of the following best describes a cyber attack?

A cyber attack is best described as an intentional offensive action against computer systems. This definition emphasizes the deliberate nature of the actions taken by the attacker, who seeks to exploit vulnerabilities for various reasons such as theft, disruption, or data manipulation. These actions can take many forms, including malware deployment, phishing attempts, or denial-of-service attacks, all of which are aimed at compromising the integrity, confidentiality, or availability of information systems.

Other options do not fit the definition of a cyber attack. For instance, a natural disaster affecting IT systems refers to external environmental factors such as storms or earthquakes that can cause damage, but these are not intentional actions. Similarly, a failure in technology that affects operations points to system malfunctions or hardware issues, which do not involve human malicious intent. Lastly, unintentional damage to physical hardware implies accidents or unplanned incidents that also lack the targeted intention characteristic of cyber attacks. Hence, option A is the most accurate representation of a cyber attack.