Corewar is project in two part : the VM and the ASM.
the asm, like the real one, translate code into binary.
the VM is the arena where the binaries are load to fight.
the winner binary is the last one to perform a live opertion.
You can see all the operation at : https://docs.google.com/spreadsheets/d/1pFwSCne-mh-u5ZLsjZS8VI9QvecYk-gWTyNaPstjpLE/edit#gid=0
For more informations on the rule, see : https://github.com/VBrazhnik/Corewar/wiki