Real-time monitoring identifies the full firmware modification chain: a device entering firmware-update mode, receiving a large data transfer on a firmware-capable protocol port from a source not in the approved engineering workstation list, rebooting, and reporting a post-reboot firmware hash that does not match the authorized inventory. This technique-level analytic synthesizes System Firmware (T1693.001) and Module Firmware (T1693.002). OT operational-fidelity gate: Alert only when the action is not attributable to an authorized operator/engineering source for the specific target and function, and it is either outside an approved change/maintenance window or lacks matching change-control context; where telemetry permits, require corroborating device, configuration, or process-state effect. Suppress activity that fully matches approved maintenance, commissioning, failover, recovery, or tested control procedures.
| Data Component | Name | Channel |
|---|---|---|
| Firmware Modification (DC0004) | assetinventory:FirmwareHash | post-reboot firmware hash (main processor or specific module) not in authorized firmware inventory |
| Device Alarm (DC0108) | operationaldb:AlarmEvent | device reboot within firmware update window of the flagged transfer session |
| Network Traffic Content (DC0085) | NSM:Content | large session on firmware-capable port from source not in engineering workstation list outside change control window |
| Field | Description |
|---|---|
| AuthorizedFirmwareInventory | Cryptographic hash inventory of authorized firmware versions, covering both main processor and module-level firmware. |
| ChangeControlWindow | Scheduled maintenance periods during which firmware updates are authorized. |
| EngineeringWorkstationList | IP allowlist of workstations authorized to perform firmware updates. |
| FirmwareUpdateWindow | Time window within which a device reboot following a large transfer session is considered part of the same firmware update event. |