Detections

Real-time monitoring identifies multiple field devices becoming unreachable simultaneously following a network infrastructure configuration change event. 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.

Real-time monitoring identifies an Industrial Control System (ICS) protocol file-transfer service such as Distributed Network Protocol 3 (DNP3) File Transfer Object or Internet Electrotechnical Commision (IEC) 61850 file service being used to place files on a field device from a source not in the approved engineering workstation list, outside a scheduled maintenance window, where the transfer source is a device not previously enrolled. OT operational-fidelity gate: Alert only when the account/device/session violates the approved identity + source host/jump path/zone policy and is corroborated by access to a protected OT asset, execution, configuration change, or another security-relevant follow-on event. Suppress approved shift activity, vendor support, break-glass use, commissioning, and documented remote-access windows.

Real-time monitoring identifies an Industrial Control System (ICS) protocol file-transfer service placing a file on a field device from a source not in the approved engineering workstation list, where the transferred filename pattern matches firmware images or executable payloads inconsistent with the device's normal data exchange profile. OT operational-fidelity gate: Alert only when execution violates an approved signer/hash/path/parent/process or tool allowlist, or originates from an unauthorized user/tool, and is tied to an OT asset or follow-on OT-relevant action. Suppress vendor-signed software, approved engineering utilities, diagnostics, patching, backup, and documented maintenance.

Real-time monitoring identifies an Industrial Control System (ICS) protocol restart command directed at a field device from a source not in the approved engineering workstation list, where multiple devices receive restart commands within a short window. 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.

Real-time monitoring identifies an ICS device presenting protocol identity attributes (for example vendor, product, model, or capability identifiers) that conflict with the identity and capabilities recorded for that network address/device in the authorized asset inventory. OT operational-fidelity gate: Alert only when execution violates an approved signer/hash/path/parent/process or tool allowlist, or originates from an unauthorized user/tool, and is tied to an OT asset or follow-on OT-relevant action. Suppress vendor-signed software, approved engineering utilities, diagnostics, patching, backup, and documented maintenance.

Real-time monitoring identifies Industrial Control System (ICS) protocol messages querying network topology information from embedded devices -- neighbor device lists, Common Industrial Protocol (CIP) port object information -- from a source not in the approved control server list. OT operational-fidelity gate: Do not alert on novelty, scan/read volume, or enumeration alone. Alert when the source role is not authorized for discovery/polling and the target scope, address/tag range, protocol, or rate deviates from the established operational baseline. Suppress normal SCADA/HMI/historian polling, commissioning, asset inventory, backup, diagnostics, and approved engineering activity.

Real-time monitoring identifies broadcast discovery frames on the Industrial Control System (ICS) network from a source Media Access Control (MAC)/Internet Protocol (IP) address not in the approved device inventory. OT operational-fidelity gate: Do not alert on novelty, scan/read volume, or enumeration alone. Alert when the source role is not authorized for discovery/polling and the target scope, address/tag range, protocol, or rate deviates from the established operational baseline. Suppress normal SCADA/HMI/historian polling, commissioning, asset inventory, backup, diagnostics, and approved engineering activity.

Real-time monitoring identifies a new Internet Group Management Protocol (IGMP) group join or multicast subscription from a source Media Access Control (MAC)/Internet Protocol (IP) not in the approved device inventory, particularly for protection-relay Generic Object Oriented Substation Event (GOOSE) datasets. OT operational-fidelity gate: Do not alert on novelty, scan/read volume, or enumeration alone. Alert when the source role is not authorized for discovery/polling and the target scope, address/tag range, protocol, or rate deviates from the established operational baseline. Suppress normal SCADA/HMI/historian polling, commissioning, asset inventory, backup, diagnostics, and approved engineering activity.

Real-time monitoring identifies Hypertext Transfer Protocol (HTTP) requests to an embedded device's management web interface containing exploit-pattern content (oversized parameters, directory traversal sequences) from a source not in the approved engineering workstation list. OT operational-fidelity gate: Alert only when execution violates an approved signer/hash/path/parent/process or tool allowlist, or originates from an unauthorized user/tool, and is tied to an OT asset or follow-on OT-relevant action. Suppress vendor-signed software, approved engineering utilities, diagnostics, patching, backup, and documented maintenance.

Real-time monitoring identifies Industrial Control System (ICS) unsolicited response messages such as Distributed Network Protocol 3 (DNP3) unsolicited or Generic Object Oriented Substation Event (GOOSE) frames arriving from Internet Protocol (IP) or Media Access Control (MAC) addresses that do not match the enrolled device for those data points. 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.

Real-time monitoring identifies a field device or serial gateway receiving Industrial Control System (ICS) protocol traffic relayed through an intermediate host, identifiable by protocol-level timing anomalies or L2 source address changes where the device Internet Protocol (IP) address responds from a Media Access Control (MAC) address different from its enrolled hardware address. OT operational-fidelity gate: Alert only when the asset's documented role does not permit the connection and the destination/proxy/service is outside the approved communications profile, with process/service identity used as corroboration where available. Suppress approved vendor support, update repositories, remote operations, failover paths, and documented temporary connectivity.

Real-time network monitoring identifies a field device's source Media Access Control (MAC) address changing without a corresponding documented hardware replacement, combined with protocol-level anomalies (transaction identifier reuse, function-code patterns deviating from baseline) for traffic associated with that device Internet Protocol (IP) address. OT operational-fidelity gate: Alert only when the asset's documented role does not permit the connection and the destination/proxy/service is outside the approved communications profile, with process/service identity used as corroboration where available. Suppress approved vendor support, update repositories, remote operations, failover paths, and documented temporary connectivity.

Real-time monitoring identifies Open Platform Communications (OPC) Unified Architecture (UA) method invocations or International Electrotechnical Commission (IEC) 61850 Abstract Common Services Interface (ACSI) service requests arriving at a field device from a client identity not in the approved application allowlist, where the invoked method is a write or control operation rather than read/subscribe. OT operational-fidelity gate: Alert only when execution violates an approved signer/hash/path/parent/process or tool allowlist, or originates from an unauthorized user/tool, and is tied to an OT asset or follow-on OT-relevant action. Suppress vendor-signed software, approved engineering utilities, diagnostics, patching, backup, and documented maintenance.

Real-time monitoring identifies malformed, oversized, or out-of-spec ICS protocol messages sent to an embedded field device from an unexpected or unauthorized source. OT operational-fidelity gate: Alert only when execution violates an approved signer/hash/path/parent/process or tool allowlist, or originates from an unauthorized user/tool, and is tied to an OT asset or follow-on OT-relevant action. Suppress vendor-signed software, approved engineering utilities, diagnostics, patching, backup, and documented maintenance.

Real-time monitoring identifies an Industrial Control System (ICS) field device or embedded engineering terminal receiving malformed or exploit-payload data via its built-in communication interface from an external source, designed to exploit a vulnerability in the device's communication stack. OT operational-fidelity gate: Alert only when the account/device/session violates the approved identity + source host/jump path/zone policy and is corroborated by access to a protected OT asset, execution, configuration change, or another security-relevant follow-on event. Suppress approved shift activity, vendor support, break-glass use, commissioning, and documented remote-access windows.

Real-time monitoring identifies Industrial Control System (ICS) protocol messages using embedded device built-in utilities or vendor-supplied diagnostic tools to execute payloads, from sources not in the approved engineering workstation list, containing payloads inconsistent with legitimate diagnostic use. OT operational-fidelity gate: Alert only when execution violates an approved signer/hash/path/parent/process or tool allowlist, or originates from an unauthorized user/tool, and is tied to an OT asset or follow-on OT-relevant action. Suppress vendor-signed software, approved engineering utilities, diagnostics, patching, backup, and documented maintenance.

Detect embedded hooking by correlating an independently acquired firmware/module integrity measurement that differs from the approved vendor/baseline image with protocol-response behavior that also departs from the device's known deterministic behavior. A protocol-response anomaly by itself does not prove a hook because firmware versions, device state, communications faults, and vendor-specific behavior can produce response differences. Treat network anomalies as corroboration and require independent integrity evidence or vendor/device attestation before escalating the condition as firmware-level hooking. Monitoring mode: periodic or event-triggered integrity verification plus near-real-time protocol monitoring where a capable OT protocol decoder is deployed.

Real-time monitoring identifies Industrial Control System (ICS) protocol sessions that bulk-read configuration data, program blocks, or data record objects from field devices -- function code sequences retrieving entire data dictionaries rather than operational process values -- from a source with no prior history of configuration-read sessions. OT operational-fidelity gate: Do not alert on novelty, scan/read volume, or enumeration alone. Alert when the source role is not authorized for discovery/polling and the target scope, address/tag range, protocol, or rate deviates from the established operational baseline. Suppress normal SCADA/HMI/historian polling, commissioning, asset inventory, backup, diagnostics, and approved engineering activity.

Real-time monitoring identifies Industrial Control System (ICS) field device event logs being cleared via ICS protocol commands from a source not in the approved engineering workstation list, occurring immediately following other suspicious ICS activity on the same device. OT operational-fidelity gate: Alert only when execution violates an approved signer/hash/path/parent/process or tool allowlist, or originates from an unauthorized user/tool, and is tied to an OT asset or follow-on OT-relevant action. Suppress vendor-signed software, approved engineering utilities, diagnostics, patching, backup, and documented maintenance.

Real-time monitoring identifies Industrial Control System (ICS) protocol messages using vendor-specific or undocumented function codes that access device hardware registers directly rather than through the normal ICS application layer, from a source not in the approved engineering workstation list. OT operational-fidelity gate: Alert only when execution violates an approved signer/hash/path/parent/process or tool allowlist, or originates from an unauthorized user/tool, and is tied to an OT asset or follow-on OT-relevant action. Suppress vendor-signed software, approved engineering utilities, diagnostics, patching, backup, and documented maintenance.

Real-time monitoring identifies Industrial Control System (ICS) protocol sessions that bulk-read configuration data, program blocks, or data record objects from field devices, covering address ranges never queried by legitimate Supervisory Control and Data Acquisition (SCADA), suggesting systematic extraction of ICS design documentation. OT operational-fidelity gate: Do not alert on novelty, scan/read volume, or enumeration alone. Alert when the source role is not authorized for discovery/polling and the target scope, address/tag range, protocol, or rate deviates from the established operational baseline. Suppress normal SCADA/HMI/historian polling, commissioning, asset inventory, backup, diagnostics, and approved engineering activity.

Real-time monitoring identifies an Industrial Control System (ICS) protocol command sequence that erases device memory, from a source not in the approved engineering workstation list, where the device subsequently becomes unresponsive or requires re-commissioning. 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.

Real-time monitoring identifies Industrial Control System (ICS) protocol requests targeting device identification and system metadata objects from a source not in the approved control server list, specifically aimed at device metadata rather than process values. OT operational-fidelity gate: Do not alert on novelty, scan/read volume, or enumeration alone. Alert when the source role is not authorized for discovery/polling and the target scope, address/tag range, protocol, or rate deviates from the established operational baseline. Suppress normal SCADA/HMI/historian polling, commissioning, asset inventory, backup, diagnostics, and approved engineering activity.

Real-time monitoring identifies Hypertext Transfer Protocol (HTTP) requests to an embedded Human-Machine Interface (HMI) panel's built-in web server capturing screen images, or Virtual Network Computing (VNC) connections to embedded HMI panels, from source Internet Protocol (IP) addresses not in the approved operator workstation list. OT operational-fidelity gate: Do not alert on novelty, scan/read volume, or enumeration alone. Alert when the source role is not authorized for discovery/polling and the target scope, address/tag range, protocol, or rate deviates from the established operational baseline. Suppress normal SCADA/HMI/historian polling, commissioning, asset inventory, backup, diagnostics, and approved engineering activity.

Real-time monitoring identifies Virtual Network Computing (VNC) or proprietary remote console sessions to embedded Human-Machine Interface (HMI) panels or operator terminals from IP addresses outside the approved Network Management System (NMS) Classless Inter-Domain Routing (CIDR) subnet, where the sessions access Industrial Control System (ICS) control interfaces with physical-plant impact. OT operational-fidelity gate: Alert only when the account/device/session violates the approved identity + source host/jump path/zone policy and is corroborated by access to a protected OT asset, execution, configuration change, or another security-relevant follow-on event. Suppress approved shift activity, vendor support, break-glass use, commissioning, and documented remote-access windows.