[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) \(**Right Click -> Modify Method** to change something inside a function\).
You cloud also try [https://www.jetbrains.com/es-es/decompiler/](https://www.jetbrains.com/es-es/decompiler/)
Then save the new file on _**File >> Save module...**_:
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**.
Then, if your .Net application is being **run** by **IIS** you can **restart** it with:
```text
iisreset /noforce
```
Then, in order to start debugging you should close all the opened files and inside the **Debug Tab** select **Attach to Process...**:
Then select **w3wp.exe** to attach to the **IIS server** and click **attach**:
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**_:
Click any module on **Modules** and selec**t Open All Modules**:
Right click any module in **Assembly Explorer** and click **Sort Assemblies**:
* **Load rundll32** \(64bits in C:\Windows\System32\rundll32.exe and 32 bits in C:\Windows\SysWOW64\rundll32.exe\)
* Select **Windbg** debugger
* Select "**Suspend on library load/unload**"
* Configure the **parameters** of the execution putting the **path to the DLL** and the function that you want to call:
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.
But, how can you get to the code of the DLL that was lodaded? Using this method, I don't know how.
### Using x64dbg/x32dbg
* **Load rundll32** \(64bits in C:\Windows\System32\rundll32.exe and 32 bits in C:\Windows\SysWOW64\rundll32.exe\)
* **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
* Change _Options --> Settings_ and select "**DLL Entry**".
* 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**:
Then, looking to this ca see when the execution was stopped in the dll you want to debug.
You should try ****[**scdbg**](http://sandsprite.com/blogs/index.php?uid=7&pid=152).
It will tell you things like **which functions** is the shellcode using and if the shellcode is **decoding** itself in memory.
```bash
scdbg.exe -f shellcode # Get info
scdbg.exe -f shellcode -r #Run it
scdbg.exe -f shellcode -r #Run it with hooks
scdbg.exe -f shellcode -d #Dump decoded shellcode
scdbg.exe -f shellcode /findsc #Find offset where starts
```
To **run a shellcode** you can also use: [http://mcdermottcybersecurity.com/articles/windows-x64-shellcode\#testing](http://mcdermottcybersecurity.com/articles/windows-x64-shellcode#testing)
This ofuscator change all the instructions for `mov`\(yeah, really cool\). It also uses interruptions to change executions flows. For more information about how does it works:
If you are lucky [demovfuscator ](https://github.com/kirschju/demovfuscator)will deofuscate the binary. It has several dependencies
```text
apt-get install libcapstone-dev
apt-get install libz3-dev
```
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)
