Methods and systems for visualizing, analyzing, archiving and securing computer and internet of things (IoT) data networks are disclosed. The system includes a data collection device (sensor), preprocessing unit, analysis unit containing at least the Koopman mode analysis unit, and a postprocessing unit. The methods include Koopman mode analysis, support vector machines or deep learning used to compute the baseline, detect and rank known and unknown threats to the system, visualize and archive them.