As a network administrator, you are reviewing the server logs and notice a surge in denied connections from various external IP addresses outside of business hours. What is the most likely reason for observing these entries in the logs?
It is a normal occurrence due to the server's performance issues during off-peak hours.
It indicates potential unauthorized access attempts that have been blocked by the firewall.
It indicates a Distributed Denial of Service (DDoS) attack targeting your server.
It shows there is a misconfiguration within your internal access control lists (ACLs).