Go to the middle of the instruction
I am trying to test some anti-parsing methods. One of them jumps to the middle of the instruction, like in this image:
When using code
mov ax, 05EBh
xor eax, eax
jz -7
db 0xE8
in a small program with NASM I get the following error:
": Win32 COFF does not correctly support relative references to absolute addresses"
Any idea how to fix this or which tool to use instead of NASM?
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If you want to go to the address where the instruction starts jz
, minus 7 bytes, you can do so with:
jz $-7
In NASM Guide :
$
evaluates the assembly position at the beginning of the line containing the expression
Note that there are commands mov
and xor
only 6 bytes, so you have to jump 1 byte before starting mov
. To jump according to your pattern, you must usejz $-4
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