Android apps under the microscope

This Note originally published on my Personal Blog here. Read original note so that you won’t miss any content.

Would you like to look under the hood of any android app?

You are welcome! (:

Precondition

• dex2jar — tool for converting .dex file to .class files

$ brew install dex2jar

• jd-gui — tool for decompiling and analysing Java “byte code”

$ brew cask install jd-gui

Let’s go

1. First of all we should get the .apk. If you haven’t one, you are able to download it from store (for more info read this xcnote).

2. Then we need to convert our .apk into the classes (.jar):

$ d2j-dex2jar test.apk -o test.jar

3. Eventually we should just decompile received .jar and look under the hood:

$ open -a jd-gui test.jar

Conclusion

Today we affect two awesome tools — dex2jar and jd-gui. Suggest you to put them into practice. Perhaps it will be a deeply fascinating diving in reverse engineering. If you have any questions, feel free to put them in the comments.

See you later (: