VB Decompiler

nade · New User Joined: 08 Oct 2007 Posts: 2

I am not sure where to ask this question.

I have written a few wrappers in c++ for applications also written in c++.

I wanted to see if I could hook some functions in a visual basic executable.

Here is how my hook works:

You make a dll and include all the exports (msvbvm60.dll) has. Like in my def file below. Now for hooking I do what I always do and in this case it would be something like

sarge · Moderator Joined: 24 Sep 2002 Posts: 194

1. Hooking into VB executables has been around a long time, you should be able to find some "secrets" using a search engine on the 'net.

2. I'm sure you know that DLL's themselves don't "execute" by themselves, they are just libraries that the executable makes use of.

3. The "VM" in "MSVBVM..." stands for VirtualMachine. This implies that it is more than just a library of exported functions. So...

4. Yes, based on item #3 above, msvbvm60.dll does a lot more than provide exported functions, it is the "engine" for VB code that actually executes the code in the executable. Even for a DLL, whose functions are called by the exectuable, the VM is required to execute those functions.

Sarge

nade · New User Joined: 08 Oct 2007 Posts: 2

I don't think you understand. Detouring functions in vb programs is not a problem.

There is nothing on the internet about a "proxy" dll for this kind of project.

It doesn't matter that it does more then export functions - all calls are redirected back to the original dll.

I just thought a wrapper would be a cleaner solution then hooking 124809 times.

sarge · Moderator Joined: 24 Sep 2002 Posts: 194

Yup, you're right...
"I don't think you understand."

I interpreted your post to mean, "How do I hook into a VB function?", or, more loosely, as something like "How can I intercept the VB messagebox (or whatever) function to make it call my own messagebox function?". That is, you are both redirecting the link, and sub-classing the existing VB message box.

It appears now, as I read your second post, that you want to wrap the entire VM, not just a few functions here-and-there (or am I wrong again?). I've not done that, so I can't comment with authority, but two thoughts:
1. You put in " the functions that the program needs". Are you sure you got them all, whatever they may be?
2. The VM has it's own dependencies on other dll's. Have you made sure to include/link them into your hook?

Other than that......???

Sarge