What defines a 'security incident' in IT?

A 'security incident' in IT is defined as any event that compromises the confidentiality, integrity, or availability of information systems or data. This definition encompasses a wide range of scenarios where sensitive information may be accessed, altered, or destroyed due to unauthorized actions or breaches.

By focusing on confidentiality, integrity, and availability—the core principles of information security—this definition helps organizations identify and respond to events that threaten their security posture. For instance, if unauthorized access occurs to a system containing sensitive data, or if an employee's actions lead to the loss of data integrity, these are both considered security incidents.

The other options do not adequately capture the essence of a security incident. The loss of hardware components primarily concerns physical assets rather than the security implications tied to data handling. A failure in internet connectivity may impact usability but does not inherently pose a threat to security itself. Likewise, a scheduled maintenance event, while important for system reliability, is a planned activity that should not result in any compromise to security. Thus, only the definition provided captures the breadth of circumstances that qualify as a security incident in the IT domain.