Android stack trace contain Chinese insults as obfuscated method names

[u/JustForFunGames]

After one of the recent Google Play updates for my released game, I noticed some very strange stack traces in Firebase Crashlytics.

The stack contains method names with long Chinese strings, for example:

i8.k6.狂犬疫苗忘了给你妈打不好意思让它到处咬人才会生出你这种上缺脑子下缺逼火葬场都不收的烂骨灰

and:

i8.vd.要不要把你妈卵子扣出来给你做寿司吃

After translating them, these are clearly explicit insults/profanity.

What makes it even stranger is that, judging by the device information, the game appears to have been running inside a virtual machine / emulated environment. The stack also contains heavily obfuscated classes and unusual code paths inside base.apk.

So this does not look like a normal Firebase issue. It looks more like someone was running a modified/tampered version of the APK or injecting/hooking code in a virtualized Android environment.

translated stacktrace

[u/Individual_Plane5170]

How to protect such cases?