T0855: Unauthorized Command Message
Adversaries may send unauthorized command messages to instruct control system assets to perform actions outside of their intended functionality, or without the logical preconditions to trigger their expected function. Command messages are used in ICS networks to give direct instructions to control systems devices. If an adversary can send an unauthorized command message to a control system, then it can instruct the control systems device to perform an action outside the normal bounds of the device's actions. An adversary could potentially instruct a control systems device to perform an action that will cause an Impact. [1]
In the Dallas Siren incident, adversaries were able to send command messages to activate tornado alarm systems across the city without an impending tornado or other disaster. [2] [3]
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Unauthorized Command Message
Adversaries may send unauthorized command messages to instruct control system assets to perform actions outside of their intended functionality, or without the logical preconditions to trigger their expected function. Command messages are used in ICS networks to give direct instructions to control systems devices. If an adversary can send an unauthorized command message to a control system, then it can instruct the control systems device to perform an action outside the normal bounds of the device's actions. An adversary could potentially instruct a control systems device to perform an action that will cause an Impact. [1]
In the Dallas Siren incident, adversaries were able to send command messages to activate tornado alarm systems across the city without an impending tornado or other disaster. [2] [3]
How security teams should use this page
Treat this object as behavior context, not an attribution claim. Validate the related groups, software, data sources, and mitigations against official ATT&CK relationships and your own telemetry before making control-coverage decisions.
Related techniques
This mirrors the MITRE pattern of making group, software, campaign, and technique relationships scannable. Relationship notes come from mirrored ATT&CK relationship text when available.
| Domain | ID | Name | Relationship / procedure |
|---|---|---|---|
| ICS | T1692.001 | Command Message Sub-technique | This object revoked by Command Message. |
All related ATT&CK context
Object version and sync metadata
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Imported snapshots across ATT&CK releases (1)
| Release | Bundle imported | Object version | Modified | Status | Raw hash |
|---|---|---|---|---|---|
| 19.1 | 1.2 | Current bundle Revoked | 2944cd34da59… |
Mirrored ATT&CK source object
The raw object is retained through the mirrored ATT&CK source bundle and object hash. The raw endpoint returns the exact object from the mirrored bundle when available.
External references and citations
MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.
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[1]
Bonnie Zhu, Anthony Joseph, Shankar Sastry 2011
Bonnie Zhu, Anthony Joseph, Shankar Sastry 2011 A Taxonomy of Cyber Attacks on SCADA Systems Retrieved. 2018/01/12
Open source URL -
[2]
Zack Whittaker April 2017
Zack Whittaker 2017, April 12 Dallas' emergency sirens were hacked with a rogue radio signal Retrieved. 2020/11/06
Open source URL -
[3]
Benjamin Freed March 2019
Benjamin Freed 2019, March 13 Tornado sirens in Dallas suburbs deactivated after being hacked and set off Retrieved. 2020/11/06
Open source URL -
[4]
mitre-attack T0855Open source URL
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