How to code keylogger in C programming language: C codechamp has brought you a detailed tutorial on how to write a keylogger code in C programming. It captures all the keys and writes them to a file, such as log.txt, and stores it on the computer hard disk.
C program of keylogger or keystroke logger: Keylogger is a computer program which captures all the key strokes pressed by the user in real time. Sending these logs to emails or FTP address depends upon the type of keylogger: 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, it does require your victim to have an internet connection. Today we will be writing a C program of a physical keylogger or keystroke logger which requires physical access of the system. We will then extend our logic in further programs to make it a remote keylogger which sends logs to FTPs and emails directly. First, let’s see how a simple keylogger program works.
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 looping to make it run in all conditions.
6. Add Sleep() function to reduce the CPU usage to 0%.
Now let us see the C program of keylogger or keystroke logger which intercepts all the keys pressed by the user and stores these pressed keys in log file.