The msfpayload component of Metasploit allows you to generate shellcode, executables, and much more for use in exploits outside of the Framework。msfpayload -h
Metasploit’s developers offer msfencode, which helps you to avoid bad characters and evade antivirus and IDSs by encoding the original payload in a way that does not include “bad” characters. Enter msfencode -h to see a list of msfencode options. x86/shikata_ga_nai encoder ，msfencode -l，The payloads are ranked in order of reliability.
nasm_shell.rb 在做汇编是很有用，给指定的汇编命令找出他们的opcode代码