Get the Whitepaper called Pozzo and Lucky, The phantom Shell. Stego in TCP/IP Part 2.
You can download it from the following link: https://packetstormsecurity.com/files/download/140115/pozzoandlucky.pdf
Source: https://packetstormsecurity.com/files/140115/Pozzo-And-Lucky-The-Phantom-Shell.-Stego-In-TCP-IP-Part-2.html