Code:xor eax, eax
xor ebx, ebx
mov esi, *start adress of your code to crypt*
mov edi, esi
start:
lodsb
add bl, 25 ; changeable!
add bh, 33 ; changeable!!
add ah, 23 ; changeable!!
add al, ah
xor al, bl
sub al, bh
stosb
cmp esi, *end adress of your code to crypt*
jle start
jmp OEP