الصمام الثنائي الضوئي MetaDefender Optical Diode

A China-nexus threat group held a foothold inside U.S. critical infrastructure for more than five years before anyone detected it.[1] A separate campaign targeting aerospace and defense specifically averaged 393 days of undetected presence.[2] In both cases, the adversary did not force entry. They arrived inside a file, through a supplier, or across a network boundary that was enforced but never inspected.