Which of the following best describes a "Threat Event"?

A "Threat Event" is accurately described as a contact event that results in a loss. This definition encapsulates the essence of what a threat event entails: it represents an actual occurrence where a threat has manifested and caused harm or potential harm to an organization. The focus is on the impact of the event, emphasizing that it directly leads to a detrimental effect, such as asset loss, financial impact, or damage to reputation.

In contrast, the other options do not align with the definition of a threat event. A planned analysis procedure describes a systematic approach to evaluating risks or vulnerabilities, which is not the same as an event occurring. A theoretical model of a potential threat suggests a conceptual framework without direct real-world implications, thus lacking the immediate impact associated with a threat event. A formal report of a security incident, while related to events, generally outlines incidents that have already occurred rather than the active occurrence of a threat event itself, which focuses on the encounter and its consequences at the moment of occurrence.