Submitted by Here is an article explaining how shellcodes work: “This article is not a guide on writing exploits, nor an overview of popular vulnerabilities. This is a step-by-step guide on developing a shellcode, a crucial point of any exploit software. Hopefully, learning how they work will help conscientious and respectable developers and system administrators to understand how malefactors think and to defend their systems against them.”
I only skimmed through this article, but from what I saw I think I still like Aleph One’s old classic article more.
The article[1] Marcellus is referring to is from Phrack[2]. There are many other security related articles there as well.
[1] http://www.phrack.org/show.php?p=49&a=14
[2] http://www.phrack.org
Had not heard the term, “shellcode”, when I was a boy we called it a, “nop slide”, and the payload in, “machine code”. Great, really great article, everyone should know what they’re up against.
a “nop slide” is a technique used when you aren’t sure exactly what address EIP will point to after an overflow. Afaik, shellcode has always been the name for the machine instruction code being passed. The article is very good, but there are easier ways to avoid nulls by doing simple bitshifting using XOR.