Network Anomaly: Tunneling via Legitimate Services
This rule detects anomalous network connections originating from common communication applications (Teams, Slack, Discord, Skype) to non-standard ports (not 80, 443, 8080, 8443) and to IP addresses not typically associated with Microsoft or other major cloud providers (e.g., not starting with 13. or 51.). It specifically looks for a high volume of such connections (10 or more within an hour) from a single process on a device, which could indicate protocol tunneling or the use of these applications for command and control.
Microsoft Sentinel (KQL)
