Shellcode-Basics-NASM

Intel (NASM) x86_64 Assembly

A humble collection of simple things intel (NASM) x86_64 assembly

Extracting Shellcode

Assemble elf with gcc

gcc -nostdlib assembly.s -o elf-filename

Extract shellcode

objcopy --dump-section .text=shellcode-filename elf-filename

Check elf

objdump -M intel -d elf-filename

Resources

General:

• https://nets.ec/Shellcode/Null-free#Removing_Nulls

Linux:

• https://hackeradam.com/x86-64-linux-syscalls/
• https://github.com/torvalds/linux/tree/master/include/uapi/asm-generic