Fixing an EXE to not call a DLL?

[redbull]

Sounds like he fixed / patched the IAT table (is that what you call it).

In the exe itself you will see parts which refer to API names (imports from the DLL) and the names of the DLL's themselves (ie Kernel32.DLL) you can edit those in a hex editor.

[Barry]

Yes, it has 2 dll entries and a DoMessage API, this must be dealing with calling the external DLL, then it jumps back into the EXE at another Entry Point to run the EXE proper, but I don't know how to find or fix it!

I think I'll go hit my friend until he tells me

[Barry]

Success!!

I think this is more luck than skill though

I loaded the EXE into IDA and searched for GetVersion/GetVersionExA, my friend said 95% of the time that's roughly how to find the program start, but not always, something to do with C/C++ compiled programs! So after finding a couple of places that called GetVersionExA and noting the addresses I then loaded the EXE into LordPE went to the Import Table and found the entries for the second import table and used 'kill ImageImportDescriptor' to kill those additional entries so they were not called anymore.

I then changed the EntryPoint in turn to the addresses I noted in IDA and got the program running, I deleted the DLL to make sure and the program runs fine This method is probably unique to this program, but I've learned something in doing so, probably all bad practice no doubt and some of you will probably be cringing with disgust at my crude methodolgy, but hey, I managed to achieve my goal