Before revision:  We have systematically studied such threats from models, methods, experiments , evaluations, and defenses . Specifically, first, we conducted a formal definition and security attribute research on UBM.
After revision:  We have systematically studied such threats from models, methods, experiments , and made a systematical probe into this new type of threat through modeling, method analysis, experiments, evaluation and anti-defense capacity tests . Specifically, first, we conducted a formal definition and security attribute research on UBM.