Detections

Real-time monitoring identifies an email client or Office application process spawning a script interpreter or shell process on an Industrial Control System (ICS) engineering or operator workstation, immediately following the opening of an email attachment. Documented across multiple ICS incident reports as a primary initial access vector. 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 master-role traffic originating from a Windows host that is not the authorized Supervisory Control and Data Acquisition (SCADA) or Distributed Control System (DCS) server. OT operational-fidelity gate: Alert only when the master/station identity or source is not authorized for the target device and command function, or when a normally authorized master violates its configured role/sequence and produces a corroborating device/process-state change. Suppress legitimate redundancy/failover, hot-standby promotion, commissioning, and approved engineering master activity.

Real-time monitoring identifies an Industrial Control System (ICS) vendor process crashing unexpectedly, immediately preceded by an unusual cross-process memory access event from a process outside the recognized security/diagnostic tool allowlist. 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 Windows serial port configuration changes on Industrial Control System (ICS) gateway hosts that would disrupt communication with serial field devices. 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) Windows host making outbound connections on HTTP/HTTPS/DNS ports to destinations outside the approved Industrial Control System (ICS) communication baseline, from processes that are not recognized Industrial Control System (ICS) vendor applications. 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 a vendor firmware update tool activating firmware-update mode on a field device from a Windows host, outside a scheduled maintenance window or by an account not in the approved firmware management role. 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 Windows process making Industrial Control System (ICS) protocol connections to device subnets from a process not in the authorized ICS applications list, structurally valid traffic from an unauthorized source. 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 Windows process sending Industrial Control System (ICS) broadcast discovery frames from a process not associated with a recognized ICS asset management or commissioning tool. 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 Windows process joining Industrial Control System (ICS) multicast groups from a process not associated with an approved ICS protection relay monitoring tool. 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 ICS protocol responses whose timing or payload structure deviates from the established device-specific per-function baseline in a pattern consistent with an intercepting relay or hook. 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 traffic on an Industrial Control System (ICS) protocol port (e.g., 502, 20000, 44818, etc.) with payload content that does not conform to the expected protocol structure for that port, suggesting non-ICS traffic tunneled over ICS port numbers to evade port-based filtering or blend with expected traffic patterns. 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 exploit-pattern ICS/network traffic, including malformed packets, out-of-spec function codes, or overflow-sized payloads, targeting ICS servers or field devices from unexpected sources. 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 network traffic to Industrial Control System (ICS) Application Programming Interface (API) ports such as 4840 used in the Open Platform Communications (OPC) Unified Architecture (UA) or vendor-specific API ports from source Internet Protocol (IP) addresses not in the approved application client list, where the traffic pattern is consistent with write/control method invocations rather than subscription/read traffic. 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.