  Constructing stealthy malware has gained increasing popularity among cyber
attackers to conceal their malicious intent. Nevertheless, the constructed
stealthy malware still fails to survive the reverse engineering by security
experts. Therefore, this paper modeled a type of malware with an "unbreakable"
security attribute-unbreakable malware (UBM), and made a systematical probe
into this new type of threat through modeling, method analysis, experiments,
evaluation and anti-defense capacity tests. Specifically, we first formalized
the definition of UBM and analyzed its security attributes, put forward two
core features that are essential for realizing the "unbreakable" security
attribute, and their relevant tetrad for evaluation. Then, we worked out and
implemented four algorithms for constructing UBM, and verified the
"unbreakable" security attribute based on our evaluation of the abovementioned
two core features. After that, the four verified algorithms were employed to
construct UBM instances, and by analyzing their volume increment and
anti-defense capacity, we confirmed real-world applicability of UBM. Finally,
to address the new threats incurred by UBM to the cyberspace, this paper
explored some possible defense measures, with a view to establishing defense
systems against UBM attacks.
