Grandoreiro STUN/MQTT C2 Tunneling from AppData Process via Side-Loaded DLL
Detects network activity associated with the Grandoreiro banking trojan, specifically identifying C2 communication tunneled over WebRTC/STUN (port 3478) or MQTT (Azure/Google Cloud services) originating from processes executing out of the AppData\Local directory. This behavior aligns with Grandoreiro's known DLL side-loading mechanism where legitimate but vulnerable binaries are used to load malicious libraries.
Sigma
