Conclusion

You've learned how to create shellcode for the x86 processor on Linux. The concepts in this chapter can be applied to writing your own shellcode for other platform and operating systems, although the syntax will be different. (You will work with different registers, or possibly an OS that doesn't have syscalls, such as Windows.)

The most important task when creating shellcode is to make it small and executable. When hacking, you need to have shellcode as small as possible so you can fit it into the most potential vulnerable buffers. Shellcode must be executable, and we worked through the most common and easiest methods of writing executable shellcode. You will learn many different tricks and variations on these methods throughout the rest of this book.