  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.
