Metamorphic Examples
metamorphic.c : This code originates from a stack overflow post and is modified to be compiled with gcc.
Polymorphic Engine
Open source simple polymorphic engin: this requires you to use nasm. NASM (netwide assembler) is an assembly language that is cross platform and easy to use. You can convert c object files to NASM using objconv. In NASM you can allocate space with NOP instructions for mkpoly to overwrite with a random decryption sequence. The makepoly function arguments include the file name, the offset of the section to encrypt, the size of the encrypted section, and the offset of the decrypt function.