Detection of Unauthorized Message

Technique Detected:  Unauthorized Message | T1692

ID: DET0902
Domains: ICS
Analytics: AN2045
Version: 1.0
Created: 22 April 2026
Last Modified: 24 April 2026

Analytics

AN2045

Unauthorized messages may be detected by reviewing the content of automation protocols, either through detecting based on expected values or comparing to other out of band process data sources. Unauthorized messages may not precisely match legitimate messages which may lead to malformed traffic, although traffic may be malformed for benign reasons. Monitor messages for changes in how they are constructed.

Monitor for anomalous or unexpected messages that may result in changes to the process operation observable via asset application logs (e.g., discrete write, logic and device configuration, mode changes, safety triggers).

Consider monitoring for Rogue Master and Adversary-in-the-Middle activity which may precede this technique.

Log Sources
Data Component Name Channel
Network Traffic Flow (DC0078) Network Traffic None
Network Traffic Content (DC0085) Traffic None