egg

n. The binary code that is the payload for buffer overflow and format string
attacks. Typically, an egg written in assembly and designed to enable remote
access or escalate privileges from an ordinary user account to administrator
level when it hatches. Also known as shellcode. The name comes from a
particular buffer-overflow exploit that was co-written by a cracker named
eggplant. The variable name egg was used to store the payload. The usage
spread from people who saw and analyzed the code.

