What would likely indicate a change in system configuration?

A change in system configuration is often indicated by the presence of open ports and security tools that are not part of the original configuration. When a system is configured, specific services and security measures are established based on the organization's requirements. Over time, if new ports are opened or additional security tools are introduced without proper authorization, it suggests alterations have been made to the system's baseline configuration. This can occur due to legitimate reasons, such as updates or new software installation, or it can be symptomatic of unauthorized changes leading to potential vulnerabilities.

The other options present valuable indicators of issues but are not as directly indicative of a configuration change. Unidentified network traffic patterns may signal suspicious activity, potentially hinting at an intrusion but not specifically pointing to configuration changes. Unexpected hardware installations, while concerning, could also be related to legitimate upgrades or expansions rather than a configuration change per se. Access to unauthorized files is primarily a security concern indicating breaches or policy violations but doesn’t necessarily reflect a change in the system’s configuration itself. Each of these factors plays an important role in incident handling, yet open ports and security tools directly reflect alterations made to the system's configuration.