The script will use msfvenom (metasploit) to generate shellcode in diferent formats ( c | python | ruby | dll | msi | hta-psh ), injects the shellcode generated into one funtion (example: python) "the python funtion will execute the shellcode in ram" and uses compilers like: gcc (gnu cross compiler) or mingw32 or pyinstaller to build the executable file, also starts a multi-handler to recibe the remote connection (reverse shell or meterpreter session).
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'shellcode generator' tool...
Generate installable binary distributions of Ruby programs for many platforms (many OS, with or without Ruby installed on clients...). Fit to distribute extensible (plugins) Ruby programs also. Handles also libraries and uploads on websites (SF.net...).