| ID | Name |
|---|---|
| T1691.001 | Command Message |
| T1691.002 | Reporting Message |
Adversaries may block or prevent a reporting message from reaching its intended target. In control systems, reporting messages contain telemetry data (e.g., I/O values) pertaining to the current state of equipment and the industrial process. By blocking these reporting messages, an adversary can potentially hide their actions from an operator.
Blocking reporting messages in control systems that manage physical processes may contribute to system impact, causing inhibition of a response function. A control system may not be able to respond in a proper or timely manner to an event, such as a dangerous fault, if its corresponding reporting message is blocked.[1][2]
| ID | Name | Description |
|---|---|---|
| C0028 | 2015 Ukraine Electric Power Attack |
During the 2015 Ukraine Electric Power Attack, Sandworm Team blocked reporting messages by using malicious firmware to render serial-to-ethernet converters inoperable. [3] |
| S0604 | Industroyer |
Industroyer uses the first COM port from the configuration file for the communication and the other two COM ports are opened to prevent other processes accessing them. This may block processes or operators from getting reporting messages from a device. [4] |
| ID | Mitigation | Description |
|---|---|---|
| M0807 | Network Allowlists |
Utilize network allowlists to restrict unnecessary connections to network devices (e.g., comm servers, serial to ethernet converters) and services, especially in cases when devices have limits on the number of simultaneous sessions they support. |
| M0810 | Out-of-Band Communications Channel |
Provide an alternative method for sending critical report messages to operators, this could include using radio/cell communication to obtain messages from field technicians that can locally obtain telemetry and status data. |
| M0814 | Static Network Configuration |
Unauthorized connections can be prevented by statically defining the hosts and ports used for automation protocol connections. |
| ID | Name | Analytic ID | Analytic Description |
|---|---|---|---|
| DET0789 | Detection of Block Reporting Message | AN1921 |
Real-time monitoring identifies iptables/nftables rules on Industrial Control System (ICS) Linux gateways that selectively drop ICS reporting message traffic based on content while allowing command traffic to pass. 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. |
| AN2198 |
Real-time monitoring identifies ACL modifications on Industrial Control System (ICS) network devices specifically blocking ICS reporting message ports while allowing command ports to remain open. 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. |
||
| AN2216 |
Real-time monitoring identifies a field device ceasing to send expected unsolicited reports or periodic status updates without a corresponding device alarm or maintenance event, while the device remains reachable via direct polling. 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. |
||
| AN2264 |
Real-time monitoring identifies Windows firewall changes blocking unsolicited Industrial Control System (ICS) reporting traffic while leaving polling/command traffic unaffected, resulting in Supervisory Control and Data Acquisition (SCADA) losing event-driven visibility while retaining polling capability. 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. |