Decompile APK built with Xamarin

Question

Good day all. I need get C# source code from an apk, I tried a few days ways, but they give me java code.

I built a little game in c# xamarin. I stopped working on it for a while, and now I want continue building it, but I've lost the source code. I have an apk file but cannot get the source code. If there is any way get the source code? Please help me.

Possible duplicate of [Is there a way to get the source code from an APK file?](http://stackoverflow.com/questions/3593420/is-there-a-way-to-get-the-source-code-from-an-apk-file) — Cee McSharpface, May 21 '17 at 13:54
and also https://forums.xamarin.com/discussion/30115/is-there-a-xamarin-android-decompiler — Cee McSharpface, May 21 '17 at 13:58
I want get C# sorse, that metod giving me java, so it is not dublicate. — Levani Titberia, May 21 '17 at 13:59
Fixed use https://www.jetbrains.com/decompiler/ decombiler. thanks all. — Levani Titberia, May 21 '17 at 14:17

Erfan Azhdari · Answer 1 · 2021-02-24T11:17:26.377

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first, extract apk using 7zip or winrar. you can also use APKTool

then go to the assemblies folder and open {appname}.dll with dnSpy or dotPeek. if you're not using Microsoft Windows, there's a cross-platform tool called AvaloniaILSpy.

if you don't see the dll file (only .so files) you need to unpack it with this tool.

I opened with dnSpy

edited Feb 24 '21 at 11:17

answered Aug 09 '18 at 06:25

Erfan Azhdari

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What if there are only `.so` files? – vrwim Feb 12 '20 at 09:31
in unity they are compiled by il2cpp and you have to load the so files in a disassembler like IDA or Ghidra. – Erfan Azhdari Feb 13 '20 at 10:53
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Since 2020, Xamarin DLLs might be compressed with LZ4 (it was introduced in this PR: https://github.com/xamarin/xamarin-android/pull/4686), so decompilers like dotPeek are not able to read them (yet). You have to decompress them manually first. This is described here: https://www.x41-dsec.de/security/news/working/research/2020/09/22/xamarin-dll-decompression/ – Andreas Fröwis Aug 09 '21 at 11:25

score 1 · Answer 2 · answered Jul 11 '20 at 18:01

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First use apktools to unpack apk

then use "https://github.com/tjg1/mono_unbundle" to unpack "libmonodroid_bundle_app.so"

then you will get <your_app_name>.dll

open it by dnSpy

answered Jul 11 '20 at 18:01

simonkimi

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The original repository is no longer available. The new address is "https://github.com/talshimoni/mono_unbundle/" – Mateusz Krawczuk Jun 19 '22 at 11:19

score 0 · Answer 3 · answered Mar 29 '23 at 09:38

Unfortunately, the above solutions are deprecated after compression APK with the LZ4 algorithm. [more detail][1]

The best solution I could find is in this GitHub project. After applying the steps on the GitHub link, I could obtain the DLLs and finally decompile them with dotPeek or another app.

Decompile APK built with Xamarin

3 Answers3

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