Multicast Discovery
Where this stands
No Sigma rule can address this — the telemetry MITRE names has no Sigma logsource behind it.
Sigma has no logsource taxonomy for ICS. MITRE's telemetry here is operational historians and controller state, which no Sigma rule can address.
What the technique is
Adversaries may perform multicast discovery requests which is when one system or device sends messages to all systems and devices in a pre-defined group on a network (or subnet) and then waits for a response. If a response is received that means the system or device that responded is live and can communicate over that protocol. Multicast discovery tends to be stealthier than broadcast discovery because every system or device on the network (or subnet) is not being messaged. One common OT protocol that has a multicast discovery mechanism is the Process Field Network (PROFINET) Discovery and Configuration Protocol (DCP) with its Identify All requests.
Read it on attack.mitre.orgWhat MITRE says you would watch
- AN2052
Monitor for anomalies related to discovery related ICS functions, including devices that have not previously used these functions or for functions being sent to many outstations. Monitor for new ICS protocol connections to existing assets or for device scanning (i.e., a host connecting to many devices) over ICS and enterprise protocols (e.g., ICMP, DCOM, WinRM). For added context on adversary enterprise procedures and background see Remote System Discovery.
Technique names and descriptions © MITRE ATT&CK®, CC BY 4.0. Not endorsed by MITRE.