I'm attempting to reverse engineer the data element of an android app - simply because i want a couple of the images, but I've come across a stumbling block. The files are in a .pak extensions i don't recognize and can't seem to do anything with. I've pushed them through bless and the file signature is 50 41 4B 00 which is slightly different to the .pak file signature i could find online. The only information I could pull was a recurring RIFF WEBPVP8X and occasionally RIFFv2. Has anyone ever come across this before ? Or can give me a heads up of how to go about actually pulling the images out? It's not for nefarious reasons - just want to make a tacky montage of the characters in the game, with a few comical paint shop edits!
I would like to give out more details, but without any information on the target application my answer will be restricted.
You have to keep in mind that the application itself will unpack these files to use them. This means that the code to read the files is bundled within the application. Looking at the code might also give you more details about the file format. You may also try hooking any methods related to reading these file to see if you can dump the real resources files at run-time.
You can use Jadx to decompile the APK to get readable Java code.
You can also use Xposed to hook the app methods at runtime and dump the genuine files.