I've been given the task of trying to recreate a DLL that has slight modifications to the original DLL, which will be executed if another program runs. Basically a mocked up version of the DLL for testing/simulating other parts of a larger system.
I've searching to see if there is any method to check if the library is COM or DCOM but have not found any. I am aware of the differences, but given a DLL library, how can I tell if it is a COM or DCOM library?
Additionally, is there any way to swap out a COM/DCOM library with a newer technology but not change parts of the code that call the COM/DCOM library?
Having the executable code alone you cannot tell which it is except that if there're proxy/stub dll shipped with it you can assume it is DCOM.
The visible differences are in how the thing is registered. Digging into registration process can be easy or not so easy depending on how registration is implemented. If registration parameters are hand-glued inside code you'd have to reverse-engineer it the harder way. If registration uses a .rgs file which is stored in resources you can just extract it and see how registration is done. Anyway your best bet is to use a VM and export its registry, then register the component, export the registry again and see the difference - what was added.