Saving KeyStrokes

This is a primitive Keylogger written in x86_64 assembly for linux.

Key learning point

• How to use System calls in linux (including sys_open, sys_read, sys_write, sys_close, and sys_exit) using asm.

Prerequisites

• Linux operating system.
• NASM assembler.
• LD linker.

Building the Keylogger

1. Create a file called keystrokes.log:

   touch keystrokes.log

2. Assemble the code:

   nasm -f elf64 script.asm -o script.o

3. Link the object file:

   ld script.o -o script

Running the Keylogger

To run the keylogger:

./script

To stop the Keylogger press CTRL + C.

To check the keys that were saved:

cat keystrokes.log