Null bytes in shellcode -


going through shellcode article on wikipedia, gives example follows:

b8 01000000    mov eax,1          // set register eax 0x000000001

to make above instruction null free, they've re-written follows:

33c0           xor eax,eax        // set register eax 0x000000000 40             inc eax            // increase eax 0x00000001

where null byte in first instruction? how converted instructions not have null byte?

the null bytes right after b8 01 in first instruction. second instruction uses xor operation 0 out eax (any x xor x = 0) , increment 1 achieve same result without 00, null byte.


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