I'm trying to change the instruction from jne to je

jne instruction

I've change an instruction

75 0c        jne [some_location]

75 0c is a 2 jump instruction.

So, I've a chaged it to from 75 0c to 74 0c which is also a 2 byte jcc instruction.

The error:

./binary: 1: 00000000:: not found
/* Repeat of the same error but instead of 0000000X where is X is some number */

EDIT: The problem was the hex editor was filtering lines and corrupting data? I was using nvim as the hex edior

  • 1
    Your question doesn't indicate what tool you're using when the error occurs. Apr 1, 2022 at 22:28
  • @RolfRolles It should be tool agnostic, right? Nothing here is really dependent on the tool I use. I use a disassembler to view the assembly and use a hex editor to edit the instruction.
    – user40683
    Apr 2, 2022 at 0:52
  • Oh, I misread. The program that you patched is generating this error, not the tool that did the patching. In any case, this question is impossible to answer. We have 3 lines of assembly code and the knowledge that if you invert a jump, the program spits out a message that it didn't produce before you patched it. What answer are you looking for beyond "you altered the logic of the program, and its behavior changed as a result"? Apr 2, 2022 at 15:19
  • We can help you better with more info on the binary - maybe attach it? Additionally any more details on the crash/error in the patched binary - maybe run it under a debugger?
    – sudhackar
    Apr 5, 2022 at 10:57
  • @RolfRolles The problem was the hex editor was filtering lines and corrupting data? I switched do a new hex editor. I was using nvim and it was filtering liines
    – user40683
    Apr 6, 2022 at 3:03

2 Answers 2


You do not need to use an hexadecimal editor with radare2. r2 is a reverse engineering framwork. It does everything.

First ensure radare2 is updated with the latest version:

git clone https://github.com/radareorg/radare2
sh radare2/sys/install.sh

Then open your program in write mode, replace NAMEOFYOURPROGRAM by the name of the program that you want to patch. Then you can overwrite the instruction:

radare2 -a x86 -b 32 -w NAMEOFYOUREXECUTABLE
=> s 0x1343
=> "wa jn 0x1351"

If you want to swap a conditional jump you can use the wao command like this: r2 -qc 'wao recj @ 0x1343' -w YOURPROGRAM.

But you can also use:

  • wx 74@0x1343
  • wai jne 0x1351@0x1343
  • woa 01@!1

(there are many other ways to achieve the same, pick the one you like more)

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