Changing a memory value.

[Spippo]

Hi all,

I'm trying to create a trainer for a flash game.
I have an AxShockwaveFlash component to play the flash game in a windows form.
With an other program (cheat engine) I found the memory place of the money-value in the game.
How can I change this value in C# .NET? When I click a button for example.

Thanks

[Plater]

You will have to use some unsafe code to do it.
Possible even create an unmanaged DLL that contains methods for doing that.

[Spippo]

Yes, I already thought it would be unsave. Writing directly into a programs memory, but any idea how to do this?

[Plater]

Honestly, I recomend using an unmanged DLL to do it. Less messy then trying to do unsafe stuff.
Create a function that say takes in two integers. One integer will be an address, one will be the value to set it to. Your unmanaged function would set the memory to be that value.
That way your C# just needs to know the memory location and the value.

[Spippo]

OK, I found something that works for writing into the memory:

To use the C/C++ functions I called these parts:

[DllImport("kernel32.dll")]
public static extern Int32 CloseHandle(IntPtr hObject);
[DllImport("kernel32.dll")]
public static extern IntPtr OpenProcess(UInt32 dwDesiredAccess, Int32 bInheritHandle, UInt32 dwProcessId);
[DllImport("kernel32.dll")]
public static extern Int32 WriteProcessMemory(IntPtr hProcess, IntPtr lpBaseAddress, uint[] lpBuffer, UInt32 nSize, IntPtr lpNumberOfBytesWritten);
[DllImport("kernel32.dll")]
public static extern Int32 ReadProcessMemory(IntPtr hProcess, IntPtr lpBaseAddress, [In, Out] byte[] buffer, UInt32 size, out IntPtr lpNumberOfBytesRead);

And I used them as followed:

Process proc = Process.GetCurrentProcess();
IntPtr procHandle = OpenProcess(0x1F0FFF, 0, (UInt32)proc.Id);
WriteProcessMemory(procHandle, (IntPtr)0x038C3148, new uint[] { 0x08 }, 4, (IntPtr)0);
byte[] b = null;
IntPtr i;
if((ReadProcessMemory(procHandle, (IntPtr)0x038C3148, b, 4, out i) != 0))
           MessageBox.Show(b.ToString());

The writing works (because the money value changes), but I don't get a messagebox, so the reading doesn't work. What am I doing wrong?
To 0x1F0FFF parameter to open the handle is "enables all possible access rights to the process specified by the Process ID."

[Plater]

The return value is the value it is reading from the memory address right?
And the out variable tells you how many bytes it's reading, is it reading any bytes?

[Spippo]

no, the variable 'i' is always 0

[Plater]

It might have something to do with how you initialized b. Seems like b is supposed to return the data read?
Try setting b to an array that has enough bytes to read, then see if i changes?

[Spippo]

Nope, still doesn't return anything and i stays 0