Calling Internal functions from a second program question.

I wanted to question how to call a function of a program with a second independent program.

First is a program that prints a int variable once every 5 seconds. It contains an uncalled function that turns the int into int++. However this function isn't called by said program.

The second program would be able call the programs uncalled function. Just wanting to know a point in the right detection.

Easiest way would be to inject a .dll that calls the function from within the process. You could also pick a function that gets called very often, many Windows functions get called several times per second, write a jump to a codecave into it, call your function in the codecave, execute the overwritten Opcodes and then return to the hooked function. This can be done without injecting a .dll.

Quote:

Originally Posted by Algaru I wanted to question how to call a function of a program with a second independent program. First is a program that prints a int variable once every 5 seconds. It contains an uncalled function that turns the int into int++. However this function isn't called by said program. The second program would be able call the programs uncalled function. Just wanting to know a point in the right detection.

You could use code injection.
Assemble your asm code to opcodes ( for example with fasm) and then inject it via CreateRemoteThread.

Or use Dll Injection.

If you have the source code for both programs you could also use IPC (for example a named pipe).

If the target routine has only one argument it would be possible to call the function directly with CreateRemoteThread.
If thats not the case you will have to inject a dll/asm-code because CreateRemoteThread is not able to deliver more than one argument.
mfg @night@