Hooking functions with code-injection

[Jacob123]

I wanted to know if it was possible to hook a certain function in this program. The function is WriteProcessMemory. Is it possible that I could MessageBox() the parameters of this function every time its called?

[packetVB]

Yes,
Done it with other API's. WriteProcessMemory would be the same.
Web Search for Import address table patching.
Actuall I got an example on my site under Projects. Look at IAT patching.

http://www.martinm.net/

[bashterror]

I'm not good at Assembly.. but i've learnt about hooking with vb... i'm just curious if it's possible to alter the ouput of a function in a process after hooking to it...
like changing the output of a process that is supposed to make some calculation.

[chemicalNova]

I'm not good at Assembly.. but i've learnt about hooking with vb... i'm just curious if it's possible to alter the ouput of a function in a process after hooking to it...
like changing the output of a process that is supposed to make some calculation.

As I understand it, you may be able to just re-write a whole function. I think I saw in parts of the Half-Life 1 SDK, that the functions used hooked the actual HL Engine functions, to re-write functions to make team-based games possible. I could possibly be wrong. Without looking at the Half-Life 1 engine source right now (which I suppose I could just download the Quake engine source!), I wouldn't know.

Looks suspiciously like it though,

chem

[Brandito]

Hmmm... where can I find more information on hooking.
Is hooking where my application "attaches" to a process and waits for an event to trigger?

I primarily develop under linux... asm, c/c++. VB examples may not help as much.

thanks!

[Raedwulf]

No i don't think so.....what hooking is:
An application calls a function. <---and you want don't want it to call that function only
1.) You can change the pointer to that function and call the old one again.
2.) You want it to call a new function.
3.) You want to modify the function at that pointer.

I believe all these circumstances come under hooking.