Outbound connection monitoring is the defensive practice of observing traffic that devices initiate to external networks. It can include reviewing destination addresses, ports, protocols, connection frequency, and data volume, then comparing them with expected behavior for each system.
This matters because compromised devices may quietly relay traffic for others, as in proxyjacking, or communicate with attacker-controlled infrastructure. Unexpected connections from network appliances or servers can reveal unauthorized software or unusual relay activity. Defenders use firewalls, network detection tools, DNS logs, and flow records to identify anomalies, investigate the process or device involved, and restrict suspicious traffic. Monitoring is most effective when paired with a baseline of normal activity and timely patching; unusual outbound traffic is a signal to investigate, not proof of compromise by itself.