Reversing a DLL is maybe illegal in US, but in other countries not necessarily. E.g. in Poland (maybe even whole EU) one can reverse engineer anything in order

Reversing a DLL is maybe illegal in US, but in other countries not necessarily. E.g. in Poland (maybe even whole EU) one can reverse engineer anything in order to make it work on their OS, hardware etc. - this is the law, it overrides any kind of EULA.