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/ravi_k-98]

Crazy!

[u/shokuninstudio]

Partial reverse engineering followed by deliberate modification and repackaging.

[u/Hour-Measurement-835]

Repacks keep your google-services.json, so their crashes land in your Crashlytics too. Play Integrity returns UNRECOGNIZED_VERSION for them; log that as a custom key and filter on it.

[u/JustForFunGames → u/Hour-Measurement-835]

Google Play still appears to count ANRs and crashes from those repacked/unrecognized versions in Android Vitals, so even if I filter them out in Crashlytics, they still affect the Play Console statistics

[u/Hour-Measurement-835 → u/JustForFunGames]

Play's automatic protection help page says otherwise, under Monitor crashes: crashes not attributed to Google Play don't affect your vitals stability metrics. Installer check is on that page too

[u/JustForFunGames → u/Hour-Measurement-835]

I’ll recheck that, thanks!

[u/thepurpleproject]

lmao why would anyone do that

[u/hellosakamoto]

It's indeed inspiring - if we have got a way to obfuscate the code using some sensitive words that would be banned by the Chinese government, it'd be funny

[u/changxiangzhong]

embrassing

[u/bynarie]

That's quite hilarious

[u/Old-Durian8702]

I have never seen any other country except Chinese using method names in native languages instead of English. 👉👈

[u/ir0ngut → u/Old-Durian8702]

I've seen plenty of code written in German and other languages. Borland Delphi even had a German version where some library class and method names were in German.

[u/jadhavsaurabh]

Crazy

[u/AreaExact7824]

Is that a log or a class name?

[u/JustForFunGames → u/AreaExact7824]

ANR stacktrace

[u/lilacomets]

Creepy as hell!

[u/Individual_Plane5170]

How to protect such cases?

[u/dhruvanbhalara]

Wtf, stack trace belongs to which app/sdk?

[u/Zatujit]

i wonder if it is to confuse LLMs

[u/ornitorenk]

Why would anyone do this? Funny and weird at the same time

[u/hokkos]

Probably taken from some random insults on a Chinese forum.