Processor-Dependent Malware... and codes

Malware usually target computers according to their operating system. Thus we have Windows malwares, Linux malwares and so on ... In this paper, we consider a different approach and show on a technical basis how easily malware can recognize and target systems selectively, according to the onboard processor chip. This technology is very easy to build since it does not rely on deep analysis of chip logical gates architecture. Floating Point Arithmetic (FPA) looks promising to define a set of tests to identify the processor or, more precisely, a subset of possible processors. We give results for different families of processors: AMD, Intel (Dual Core, Atom), Sparc, Digital Alpha, Cell, Atom ... As a conclusion, we propose two {\it open problems} that are new, to the authors' knowledge.