Complete technique description
Adversaries may send unauthorized messages to ICS systems and devices to evade defenses or manipulate processes. Unauthorized messages can be categorized as either reporting messages that contain telemetry data about the current state of systems, devices, and processes or as command messages which instruct systems and devices on how to operate. By injecting unauthorized messages, adversaries can make it appear as if everything is working correctly when it isn’t, trigger alarms to misdirect personnel or impact processes, and manipulate controls to disrupt processes.[Bonnie Zhu, Anthony Joseph, Shankar Sastry 2011]
Adversaries may send unauthorized messages in an ICS environment using software found within the environment (living-off-the-land, vendor-specific interfaces, etc.), custom tooling leveraging OT protocols and libraries, or by positioning themselves between systems and devices and injecting messages into the communications such as the case with an Adversary-in-the-Middle attack.
Official technique definition · Open in the interactive matrix
Parent and sub-techniques
Related pages are navigation context. Their tools, rules and lab results are not automatically inherited.
Detection telemetry and configuration
These contracts are selected through exact technique-to-data-component relationships or explicitly labelled planning overrides. Configure a collector at the relevant observation point; a telemetry name alone is not coverage.
Network Connection Creation · source-mapped
DC0082 collection page — Enable scoped Sysmon NetworkConnect (3), disabled by default, or a platform-equivalent process-aware network sensor.
Providers and collection configuration
- Microsoft Sysmon: Windows event-based collection; enable the event types needed below.
- Linux Audit: Linux alternative for supported system-call and file events; different semantics and fields.
- Apple Endpoint Security clients: macOS alternative where the subscribed event exists; requires an entitled, approved client, not an iOS collector.
- On a disposable Windows host, review the installed Sysmon schema and current configuration; merge scoped event filters into the existing policy rather than replacing it.
- Forward Microsoft-Windows-Sysmon/Operational to the lab collector. Preserve event ID, timestamp, computer, process identifiers and the original event.
- For Linux or macOS, select the equivalent sensor separately and test its emitted fields; a Windows event ID does not transfer across platforms.
Required normalized fields: process_guid, destination_ip, destination_port, protocol, initiated.
Illustrative collection event
Project-normalized synthetic JSON, not a native provider log, captured event, attack verdict or validated detection. A parser/adapter is required for a real SIEM. Example names, IPs and values are fictional.
{
"schema": "1200km.telemetry.example.v1",
"synthetic": true,
"timestamp": "2026-09-27T12:00:00Z",
"telemetry_id": "DC0082",
"collector": "illustrative-lab-collector",
"observation": {
"process_guid": "lab-process-001",
"destination_ip": "198.51.100.20",
"destination_port": 443,
"protocol": "tcp",
"initiated": true
}
}
Visibility limits: Event filtering and sensor versions change coverage. High-volume image-load and process-access collection needs tuning; endpoint events alone do not establish intent.
Network Traffic Content · source-mapped
DC0085 collection page — Scope approved packet capture/protocol content collection to the lab flow; retain capture provenance and truncation indicators.
Providers and collection configuration
- Zeek: Connection and protocol metadata from traffic visible to the sensor.
- Suricata EVE: Configured flow, alert, DNS, HTTP, TLS and protocol records.
- Use an authorized lab TAP/SPAN, virtual mirror or gateway interface. Define which traffic crosses it; avoid assuming visibility into every segment.
- Enable the required Zeek analyzers or Suricata EVE event types. Export logs with sensor identity, clock synchronization and flow correlation identifiers.
- Monitor capture loss, truncation and exporter sampling. Capture payload only with approval and restrictive retention; encryption normally prevents plaintext inspection.
Required normalized fields: flow_id, protocol, method, path, payload_excerpt.
Illustrative collection event
Project-normalized synthetic JSON, not a native provider log, captured event, attack verdict or validated detection. A parser/adapter is required for a real SIEM. Example names, IPs and values are fictional.
{
"schema": "1200km.telemetry.example.v1",
"synthetic": true,
"timestamp": "2026-09-27T12:00:00Z",
"telemetry_id": "DC0085",
"collector": "illustrative-lab-collector",
"observation": {
"flow_id": "lab-flow-1",
"protocol": "http",
"method": "GET",
"path": "/lab-check",
"payload_excerpt": "LAB_TELEMETRY_CHECK"
}
}
Visibility limits: Flows are not packet payloads. NAT, asymmetric routes, encryption, missing mirrors and sampling can hide attribution or content. A destination connection alone does not prove malicious intent.
Network Traffic Flow · source-mapped
DC0078 collection page — Collect Zeek conn.log, Suricata flow events or exporter equivalents, including observation point and sampling settings.
Providers and collection configuration
- Zeek: Connection and protocol metadata from traffic visible to the sensor.
- Suricata EVE: Configured flow, alert, DNS, HTTP, TLS and protocol records.
- AWS VPC Flow Logs: IP traffic metadata alternative; no packet payload or DNS answer history, and some traffic is not logged.
- Use an authorized lab TAP/SPAN, virtual mirror or gateway interface. Define which traffic crosses it; avoid assuming visibility into every segment.
- Enable the required Zeek analyzers or Suricata EVE event types. Export logs with sensor identity, clock synchronization and flow correlation identifiers.
- Monitor capture loss, truncation and exporter sampling. Capture payload only with approval and restrictive retention; encryption normally prevents plaintext inspection.
Required normalized fields: source_ip, destination_ip, destination_port, protocol, bytes_sent, bytes_received.
Illustrative collection event
Project-normalized synthetic JSON, not a native provider log, captured event, attack verdict or validated detection. A parser/adapter is required for a real SIEM. Example names, IPs and values are fictional.
{
"schema": "1200km.telemetry.example.v1",
"synthetic": true,
"timestamp": "2026-09-27T12:00:00Z",
"telemetry_id": "DC0078",
"collector": "illustrative-lab-collector",
"observation": {
"source_ip": "192.0.2.10",
"destination_ip": "198.51.100.20",
"destination_port": 443,
"protocol": "tcp",
"bytes_sent": 128,
"bytes_received": 512
}
}
Visibility limits: Flows are not packet payloads. NAT, asymmetric routes, encryption, missing mirrors and sampling can hide attribution or content. A destination connection alone does not prove malicious intent.
Simulation design and documented procedures
Atomic evidence: no compatible candidate in this snapshot. Live lab status: not run for these imported procedures.
Use a process simulator or isolated test rig with no connection to production controllers or physical actuators. Preserve safety interlocks; destructive effects require synthetic evidence, not real equipment damage.
No compatible Atomic procedure is present in this pinned evidence set. Technical feasibility has not been ruled out. A custom procedure must define the behavior, target, collection point, success observable and rollback before execution.
Technique-specific experiment contract
- Choose one procedure implementing T1692 Unauthorized Message; identify the observable behavior in the source definition, not just its tactic.
- Record exact target, tool/version, inputs, privileges, network limits and approval. Never run an imported default target automatically.
- Enable the collection sources above and verify a benign baseline reaches the detector.
- Run only the approved isolated scenario; capture native events and an independent behavior observable.
- Evaluate the exact rule/model, restore the lab, and preserve configuration, event hashes, alerts, controls and misses.