{"source_checked_on":"2026-10-19","schema_version":1,"key":"ics/T1692","id":"T1692","name":"Unauthorized Message","domain":"ics","reviewed_on":"2026-09-28","source_url":"https://attack.mitre.org/techniques/T1692","source_file":{"file":"ics.json","url":"https://raw.githubusercontent.com/mitre-attack/attack-stix-data/20664a889568dce884a1dac0ec7b12ae3a199f51/ics-attack/ics-attack-20.0.json","sha256":"c9ca0ce523a1b5e512060a390415e8aefe8f6d32c5f82d7de81264960c1e1183","bytes":5266683},"source_object_sha256":"065c197d105075277f1c02b698f382d41a2cab950a2ae89260a01d33032b7fbd","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.(Citation: Bonnie Zhu, Anthony Joseph, Shankar Sastry 2011)\n\nAdversaries 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](https://attack.mitre.org/techniques/T0830) attack.\n","references":[{"source_name":"mitre-attack","url":"https://attack.mitre.org/techniques/T1692","external_id":"T1692"},{"source_name":"Bonnie Zhu, Anthony Joseph, Shankar Sastry 2011","description":"Bonnie Zhu, Anthony Joseph, Shankar Sastry 2011 A Taxonomy of Cyber Attacks on SCADA Systems Retrieved. 2018/01/12 ","url":"http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6142258"}],"platforms":["Embedded","Windows","Linux"],"environments":["cloud-hosted-endpoint","ics-ot","onprem"],"visibility":"source_mapped","visibility_note":null,"parent":null,"children":[{"key":"ics/T1692.001","id":"T1692.001","name":"Command Message","page":"techniques/ics/T1692.001/"},{"key":"ics/T1692.002","id":"T1692.002","name":"Reporting Message","page":"techniques/ics/T1692.002/"}],"telemetry":[{"id":"DC0082","name":"Network Connection Creation","page":"telemetry/DC0082/","kind":"attack_component","category":"Endpoint activity","description":"Creation of an endpoint network connection linked to a process.","collection_focus":"Enable scoped Sysmon NetworkConnect (3), disabled by default, or a platform-equivalent process-aware network sensor.","providers":[{"name":"Microsoft Sysmon","scope":"Windows event-based collection; enable the event types needed below.","source_id":"sysmon"},{"name":"Linux Audit","scope":"Linux alternative for supported system-call and file events; different semantics and fields.","source_id":"linux"},{"name":"Apple Endpoint Security clients","scope":"macOS alternative where the subscribed event exists; requires an entitled, approved client, not an iOS collector.","source_id":"apple"}],"configuration":["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."],"configuration_example":null,"required_fields":["process_guid","destination_ip","destination_port","protocol","initiated"],"example":{"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}},"example_note":"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.","limitations":"Event filtering and sensor versions change coverage. High-volume image-load and process-access collection needs tuning; endpoint events alone do not establish intent.","sources":[{"id":"sysmon","title":"Microsoft Sysmon events and configuration","url":"https://learn.microsoft.com/en-us/sysinternals/downloads/sysmon"},{"id":"sysmon_config","title":"Microsoft Sysmon configuration files","url":"https://learn.microsoft.com/en-us/windows/security/operating-system-security/sysmon/sysmon-configuration-files"},{"id":"linux","title":"Linux Audit rule configuration","url":"https://www.man7.org/linux/man-pages/man8/auditctl.8.html"},{"id":"apple","title":"Apple Endpoint Security framework for macOS","url":"https://developer.apple.com/documentation/endpointsecurity"},{"id":"process_audit","title":"Microsoft process creation event 4688","url":"https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-10/security/threat-protection/auditing/event-4688"}],"association":"attack_component","anomaly_design":"Per host role and user: rare process/object combinations, bursts of object access or modification, and ordered parent/action sequences. Compare maintenance windows and signed software rollout activity."},{"id":"DC0085","name":"Network Traffic Content","page":"telemetry/DC0085/","kind":"attack_component","category":"Network and protocol telemetry","description":"Packet or decoded application-protocol content visible at a network sensor.","collection_focus":"Scope approved packet capture/protocol content collection to the lab flow; retain capture provenance and truncation indicators.","providers":[{"name":"Zeek","scope":"Connection and protocol metadata from traffic visible to the sensor.","source_id":"zeek"},{"name":"Suricata EVE","scope":"Configured flow, alert, DNS, HTTP, TLS and protocol records.","source_id":"suricata"}],"configuration":["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."],"configuration_example":null,"required_fields":["flow_id","protocol","method","path","payload_excerpt"],"example":{"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"}},"example_note":"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.","limitations":"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.","sources":[{"id":"zeek","title":"Zeek protocol and connection logs","url":"https://docs.zeek.org/en/current/reference/logs/index.html"},{"id":"zeek_start","title":"Zeek capture setup","url":"https://docs.zeek.org/en/current/quickstart.html"},{"id":"suricata","title":"Suricata EVE JSON output","url":"https://docs.suricata.io/en/latest/output/eve/eve-json-output.html"}],"association":"attack_component","anomaly_design":"Per source and observation point: connection rate, destination-host/port fan-out, response/failure ratio and previously unseen destinations. Compare equivalent time windows; separate authorized scanners, NAT and sampling effects."},{"id":"DC0078","name":"Network Traffic Flow","page":"telemetry/DC0078/","kind":"attack_component","category":"Network and protocol telemetry","description":"Connection/flow summaries such as endpoints, duration, byte counts and transport.","collection_focus":"Collect Zeek conn.log, Suricata flow events or exporter equivalents, including observation point and sampling settings.","providers":[{"name":"Zeek","scope":"Connection and protocol metadata from traffic visible to the sensor.","source_id":"zeek"},{"name":"Suricata EVE","scope":"Configured flow, alert, DNS, HTTP, TLS and protocol records.","source_id":"suricata"},{"name":"AWS VPC Flow Logs","scope":"IP traffic metadata alternative; no packet payload or DNS answer history, and some traffic is not logged.","source_id":"flow"}],"configuration":["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."],"configuration_example":null,"required_fields":["source_ip","destination_ip","destination_port","protocol","bytes_sent","bytes_received"],"example":{"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}},"example_note":"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.","limitations":"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.","sources":[{"id":"zeek","title":"Zeek protocol and connection logs","url":"https://docs.zeek.org/en/current/reference/logs/index.html"},{"id":"zeek_start","title":"Zeek capture setup","url":"https://docs.zeek.org/en/current/quickstart.html"},{"id":"suricata","title":"Suricata EVE JSON output","url":"https://docs.suricata.io/en/latest/output/eve/eve-json-output.html"},{"id":"flow","title":"AWS VPC Flow Logs","url":"https://docs.aws.amazon.com/vpc/latest/userguide/flow-logs.html"}],"association":"attack_component","anomaly_design":"Per source and observation point: connection rate, destination-host/port fan-out, response/failure ratio and previously unseen destinations. Compare equivalent time windows; separate authorized scanners, NAT and sampling effects."}],"detection":{"key":"ics/T1692","id":"T1692","name":"Unauthorized Message","domain":"ics","platforms":["Embedded","Windows","Linux"],"environments":["cloud-hosted-endpoint","ics-ot","onprem"],"source_url":"https://attack.mitre.org/techniques/T1692","technique_page":"techniques/ics/T1692/","page":"detections/ics/T1692/","status":"guidance_only","counts":{"sigma":0,"atlas_basic":0,"atlas_anomaly":0,"strategies":1,"analytics":3,"live_validated":0},"sigma_rules":[],"atlas_basic":[],"atlas_anomaly":[],"anomaly_types":[],"strategies":[{"id":"DET0902","name":"Detection of Unauthorized Message","url":"https://attack.mitre.org/detectionstrategies/DET0902","stix_id":"x-mitre-detection-strategy--f487a605-0acb-4b12-b157-33b75ebd9a40","relationship_id":"relationship--71f61677-4406-4484-bacb-c8de82c7e1bd","description":"","analytics":[{"id":"AN2045","name":"Analytic 2045","guidance":"Real-time monitoring identifies an Industrial Control System (ICS) protocol message arriving at a device from a source whose identity is not in the approved communication baseline for that destination, where the message is structurally valid but originates outside the documented set of legitimate communicators. This technique-level analytic synthesizes Command Message (T1692.001) and Reporting Message (T1692.002). 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.","url":"https://attack.mitre.org/detectionstrategies/DET0902#AN2045","platforms":["Embedded"],"tuning":[{"field":"ApprovedCommunicationBaseline","description":"The complete, maintained inventory of every legitimate source-to-destination communication pair in the ICS environment."}],"log_sources":[{"component_id":"DC0078","component":"Network Traffic Flow","name":"netflow:ipfix","channel":"IPFIX/NetFlow flow record (src/dst IP, src/dst port, protocol, packets/bytes/time): first-seen connection from a source to an Industrial Control System (ICS) device outside the documented approved communication matrix","platforms":["Embedded"],"analytic_id":"AN2045","source_url":"https://attack.mitre.org/detectionstrategies/DET0902#AN2045","validation":"upstream_definition_not_locally_validated","component_page":"telemetry/DC0078/"},{"component_id":"DC0085","component":"Network Traffic Content","name":"NSM:Content","channel":"structurally valid Industrial Control System (ICS) protocol message from source not in approved communication baseline for the destination device_ip","platforms":["Embedded"],"analytic_id":"AN2045","source_url":"https://attack.mitre.org/detectionstrategies/DET0902#AN2045","validation":"upstream_definition_not_locally_validated","component_page":"telemetry/DC0085/"}]},{"id":"AN2160","name":"Analytic 2160","guidance":"Real-time monitoring identifies an Industrial Control System (ICS) protocol library loaded by a Linux process not in the authorized ICS applications list, making connections to the device subnet. 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.","url":"https://attack.mitre.org/detectionstrategies/DET0902#AN2160","platforms":["Linux"],"tuning":[{"field":"ApprovedCommunicationBaseline","description":"The complete, maintained inventory of every legitimate source-to-destination communication pair in the ICS environment."}],"log_sources":[{"component_id":"DC0082","component":"Network Connection Creation","name":"auditd:SYSCALL","channel":"Linux Audit SYSCALL/EXECVE/SOCKADDR records (configured audit rule): connect syscall from an ICS service/application process to a destination outside the approved network or vendor-service baseline","platforms":["Linux"],"analytic_id":"AN2160","source_url":"https://attack.mitre.org/detectionstrategies/DET0902#AN2160","validation":"upstream_definition_not_locally_validated","component_page":"telemetry/DC0082/"}]},{"id":"AN2283","name":"Analytic 2283","guidance":"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.","url":"https://attack.mitre.org/detectionstrategies/DET0902#AN2283","platforms":["Windows"],"tuning":[{"field":"ApprovedCommunicationBaseline","description":"The complete, maintained inventory of every legitimate source-to-destination communication pair in the ICS environment."}],"log_sources":[{"component_id":"DC0082","component":"Network Connection Creation","name":"WinEventLog:Sysmon","channel":"EventCode=3 to device subnet from process not in authorized Industrial Control Systems (ICS) applications","platforms":["Windows"],"analytic_id":"AN2283","source_url":"https://attack.mitre.org/detectionstrategies/DET0902#AN2283","validation":"upstream_definition_not_locally_validated","component_page":"telemetry/DC0082/"}]}]}],"telemetry_references":[{"id":"DC0082","name":"Network Connection Creation","tag":"Network Connection Creation","page":"telemetry/DC0082/","kind":"attack_component"},{"id":"DC0085","name":"Network Traffic Content","tag":"Network Traffic Content","page":"telemetry/DC0085/","kind":"attack_component"},{"id":"DC0078","name":"Network Traffic Flow","tag":"Network Traffic Flow","page":"telemetry/DC0078/","kind":"attack_component"}],"visibility":"source_mapped","visibility_note":null,"tool_references":[],"related_parent":null,"article_url":"https://1200km.com/articles/read/2026/2026-04-20-malicious-activity-as-a-statistical-signal-a-detection-engineering-analysis-of-anomaly-bas-90df8b6dea12/","validation":{"source_join":"exact_ids","sigma_yaml":"parsed","backend_compilation":"not_run","live_telemetry":"not_run","detection_execution":"not_run"}},"tools":[],"software":[],"actors":[],"mitigations":[{"id":"M0802","name":"Communication Authenticity","url":"https://attack.mitre.org/mitigations/M0802","kind":"course-of-action","description":"Protocols used for control functions should provide authenticity through MAC functions or digital signatures. If not, utilize bump-in-the-wire devices or VPNs to enforce communication authenticity between devices that are not capable of supporting this (e.g., legacy controllers, RTUs).","relationship_id":"relationship--ea1ba63b-d0e1-4d1b-a098-72ce2c44a44a","references":[]},{"id":"M0807","name":"Network Allowlists","url":"https://attack.mitre.org/mitigations/M0807","kind":"course-of-action","description":"Use host-based allowlists to prevent devices from accepting connections from unauthorized systems. For example, allowlists can be used to ensure devices can only connect with master stations or known management/engineering workstations.(Citation: Department of Homeland Security September 2016)\n","relationship_id":"relationship--c7ae1f86-2029-4354-896b-baace526bf3c","references":[{"source_name":"Department of Homeland Security September 2016","description":"Department of Homeland Security 2016, September Retrieved. 2020/09/25 ","url":"https://us-cert.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf"}]},{"id":"M0813","name":"Software Process and Device Authentication","url":"https://attack.mitre.org/mitigations/M0813","kind":"course-of-action","description":"Devices should authenticate all messages between master and outstation assets.","relationship_id":"relationship--9ba6c904-d1bd-46dd-95fb-6da58333fa40","references":[]},{"id":"M0930","name":"Network Segmentation","url":"https://attack.mitre.org/mitigations/M0930","kind":"course-of-action","description":"Segment operational assets and their management devices based on their functional role within the process. Enabling more strict isolation to more critical control and operational information within the control environment.(Citation: Karen Scarfone; Paul Hoffman September 2009)(Citation: Keith Stouffer May 2015)(Citation: Department of Homeland Security September 2016)(Citation: Dwight Anderson 2014) ","relationship_id":"relationship--e62235fe-0546-4755-ad01-fedce306ef89","references":[{"source_name":"Department of Homeland Security September 2016","description":"Department of Homeland Security 2016, September Retrieved. 2020/09/25 ","url":"https://us-cert.cisa.gov/sites/default/files/recommended_practices/NCCIC_ICS-CERT_Defense_in_Depth_2016_S508C.pdf"},{"source_name":"Dwight Anderson 2014","description":"Dwight Anderson 2014 Protect Critical Infrastructure Systems With Whitelisting Retrieved. 2020/09/25 ","url":"https://www.sans.org/reading-room/whitepapers/ICS/protect-critical-infrastructure-systems-whitelisting-35312"},{"source_name":"Karen Scarfone; Paul Hoffman September 2009","description":"Karen Scarfone; Paul Hoffman 2009, September Guidelines on Firewalls and Firewall Policy Retrieved. 2020/09/25 ","url":"https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-41r1.pdf"},{"source_name":"Keith Stouffer May 2015","description":"Keith Stouffer 2015, May Guide to Industrial Control Systems (ICS) Security Retrieved. 2018/03/28 ","url":"https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-82r2.pdf"}]},{"id":"M0937","name":"Filter Network Traffic","url":"https://attack.mitre.org/mitigations/M0937","kind":"course-of-action","description":"Perform inline allowlisting of automation protocol commands to prevent devices from sending unauthorized command or reporting messages. Allow/denylist techniques need to be designed with sufficient accuracy to prevent the unintended blocking of valid messages.","relationship_id":"relationship--eccbcd3d-ea6e-4e9d-aa15-7b6e0909b6e0","references":[]}],"candidates":[],"simulation":{"atomic_status":"no_atomic_candidate","lab_execution":"not_run","browser_attack_runner":false,"prerequisites":"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.","scenario":null},"validation":{"source_identity":"checked_against_pinned_source","relationship_join":"exact_ids_no_inheritance","page_contract":"automated_checks_required","sensor_capture":"not_run","detection_backend":"not_run","adversary_simulation":"not_run","independent_incident_fact_check":"not_performed"},"technique_links":{"T0830":"/ttp-simulation/techniques/ics/T0830/","T1692":"/ttp-simulation/techniques/ics/T1692/"},"synthetic":{"schema":"1200km.ttp.collection-fixture.v1","synthetic":true,"technique_key":"ics/T1692","purpose":"Collection/parser contract exercise, NOT a positive example or detection of this TTP.","events":[{"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}},{"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"}},{"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}}]}}