[IC] - Investigate JA4 and JA4s connections on DeviceNetworkEvents
In DeviceNetworkEvents, we can find both JA4 and JA4S inside AdditionalFields for some TLS connections. This is interesting because we can look at both sides of the same TLS communication. We can compare clients, servers and JA4/JA4S combinations, and look for patterns or connections that behave differently from what we normally see. The following KQL extracts and decodes both fingerprints from the same network event.
Microsoft Sentinel (KQL)
