Which of the following is a sign of a potential security breach?

Unexpected changes in user access levels are indicative of a potential security breach because they may signal unauthorized access or alterations made by malicious actors. If users suddenly gain elevated privileges or if accounts are created or modified without proper authorization, it raises red flags about the integrity of the system. These changes can allow individuals to access sensitive data or modify system settings, which can compromise the overall security of the network.

In contrast, increased network speed could arise from legitimate factors such as hardware upgrades or optimizations, and does not necessarily suggest a breach. Regularly scheduled updates are typically part of a good security posture, aimed at patching vulnerabilities and improving system defenses. Consistent employee attendance does not have any direct relevance to security breaches, as it pertains more to workforce management rather than digital security. Thus, the significant deviation in access rights is a clear warning sign that demands investigation.