Saturday, May 20, 2006

The Vodafone virus dropped by today and brought us some mobile viruses to play with - thanks ! :-)

So cross-platform diffing can be fun -- Rolf ran a diff of Commwarrior.B against Commwarrior.C today, and while B is compiled for standard ARM, C is compiled in 'thumb mode', which is pretty much the same as being compiled for a different CPU (thumb means that all instructions are different).

The amusing result is that even though the compilation is for a different platform, we still get roughly 61% of the functions matched. And the functions, which are clearly the same on the 'structural' (e.g. flowgraph) - level, have completely different instructions, and manual inspection will confirm that these differing instructions end up doing the same.

For those of you that want to verify things manually, click here.

No comments: