* Use [https://webassembly.github.io/wabt/demo/wasm2wat/index.html](https://webassembly.github.io/wabt/demo/wasm2wat/index.html) to **decompile** from wasm (binary) to wat (clear text)
[ILSpy plugin for Visual Studio Code](https://github.com/icsharpcode/ilspy-vscode): You can have it in any OS (you can install it directly from VSCode, no need to download the git. Click on **Extensions** and **search ILSpy**).\
If you need to **decompile**, **modify** and **recompile** again you can use: [**https://github.com/0xd4d/dnSpy/releases**](https://github.com/0xd4d/dnSpy/releases) (**Right Click -> Modify Method** to change something inside a function).\
This is necessary because if you don't do this, at **runtime** several **optimisations** will be applied to the code and it could be possible that while debugging a **break-point is never hit** or some **variables don't exist**.
Now that we are debugging the process, it's time to stop it and load all the modules. First click on _Debug >> Break All_ and then click on _**Debug >> Windows >> Modules**_:
Then, when you start debugging **the execution will be stopped when each DLL is loaded**, then, when rundll32 load your DLL the execution will be stopped.
* **Change the Command Line** ( _File --> Change Command Line_ ) and set the path of the dll and the function that you want to call, for example: "C:\Windows\SysWOW64\rundll32.exe" "Z:\shared\Cybercamp\rev2\\\14.ridii\_2.dll",DLLMain
* Then **start the execution**, the debugger will stop at each dll main, at some point you will **stop in the dll Entry of your dll**. From there, just search for the points where you want to put a breakpoint.
Notice that when the execution is stopped by any reason in win64dbg you can see **in which code you are** looking in the **top of the win64dbg window**:
[**Cheat Engine**](https://www.cheatengine.org/downloads.php) is a useful program to find where important values are saved inside the memory of a running game and change them. More info in:
[**Blobrunner**](https://github.com/OALabs/BlobRunner) will **allocate** the **shellcode** inside a space of memory, will **indicate** you the **memory address** were the shellcode was allocated and will **stop** the execution.\
Then, you need to **attach a debugger** (Ida or x64dbg) to the process and put a **breakpoint the indicated memory address** and **resume** the execution. This way you will be debugging the shellcode.
You can find a slightly modified version of Blobrunner in the following link. In order to compile it just **create a C/C++ project in Visual Studio Code, copy and paste the code and build it**.
[**jmp2it** ](https://github.com/adamkramer/jmp2it/releases/tag/v1.4)is very similar to blobrunner. It will **allocate** the **shellcode** inside a space of memory, and start an **eternal loop**. You then need to **attach the debugger** to the process, **play start wait 2-5 secs and press stop** and you will find yourself inside the **eternal loop**. Jump to the next instruction of the eternal loop as it will be a call to the shellcode, and finally you will find yourself executing the shellcode.
[**Cutter**](https://github.com/rizinorg/cutter/releases/tag/v1.12.0) is the GUI of radare. Using cutter you can emulate the shellcode and inspect it dynamically.
Note that Cutter allows you to "Open File" and "Open Shellcode". In my case when I opened the shellcode as a file it decompiled it correctly, but when I opened it as a shellcode it didn't:
The **Create Dump** option will dump the final shellcode if any change is done to the shellcode dynamically in memory (useful to download the decoded shellcode). The **start offset** can be useful to start the shellcode at a specific offset. The **Debug Shell** option is useful to debug the shellcode using the scDbg terminal (however I find any of the options explained before better for this matter as you will be able to use Ida or x64dbg).
Upload you shellcode file as input and use the following receipt to decompile it: [https://gchq.github.io/CyberChef/#recipe=To\_Hex('Space',0)Disassemble\_x86('32','Full%20x86%20architecture',16,0,true,true)](https://gchq.github.io/CyberChef/#recipe=To\_Hex\('Space',0\)Disassemble\_x86\('32','Full%20x86%20architecture',16,0,true,true\))
This obfuscator **modify all the instructions for `mov`**(yeah, really cool). It also uses interruptions to change executions flows. For more information about how does it works:
And [install keystone](https://github.com/keystone-engine/keystone/blob/master/docs/COMPILE-NIX.md) (`apt-get install cmake; mkdir build; cd build; ../make-share.sh; make install`)
If you are playing a **CTF, this workaround to find the flag** could be very useful: [https://dustri.org/b/defeating-the-recons-movfuscator-crackme.html](https://dustri.org/b/defeating-the-recons-movfuscator-crackme.html)
I you have to reverse a Delphi binary I would suggest you to use the IDA plugin [https://github.com/Coldzer0/IDA-For-Delphi](https://github.com/Coldzer0/IDA-For-Delphi)
This plugin will execute the binary and resolve function names dynamically at the start of the debugging. After starting the debugging press again the Start button (the green one or f9) and a breakpoint will hit in the beginning of the real code.
It is also very interesting because if you press a button in the graphic application the debugger will stop in the function executed by that bottom.
## Golang
I you have to reverse a Golang binary I would suggest you to use the IDA plugin [https://github.com/sibears/IDAGolangHelper](https://github.com/sibears/IDAGolangHelper)
In [**no$gba**](https://problemkaputt.de/gba.htm), in _**Options --> Emulation Setup --> Controls**_\*\* \*\* you can see how to press the Game Boy Advance **buttons**
So, in this kind of programs, the an interesting part will be **how the program treats the user input**. In the address **0x4000130** you will find the commonly found function: **KEYINPUT.**
The last if is checking **`uVar4`** is in the **last Keys** and not is the current key, also called letting go off a button (current key is stored in **`uVar1`**).
* In any other cases, some cont (`DAT_030000d4`) is checked. It's a cont because it's adding 1 right after entering in the code.\
**I**f less than 8 something that involves **adding** values to \*\*`DAT_030000d8` \*\* is done (basically it's adding the values of the keys pressed in this variable as long as the cont is less than 8).
So, in this challenge, knowing the values of the buttons, you needed to **press a combination with a length smaller than 8 that the resulting addition is 0xf3.**
