Challenge Details

Android app reversing. The app xor decrypts a list of strings into a list of Telegram channel invite links. The channel descriptions contain some values that are used for decrypting more code that are to be executed. Each channel description decrypts a dex module to be executed. One of the dex modules will print out the flag in the logs.

The catch is that by default, the app only decrypts and executes the 1st module then stops. The flag printing module is the 18th. Players should either patch/instrument/reverse engineer the app to get the flag from there.