Hyperdimension Neptunia Re Birth1 .pac file extract?

Extraction and unpacking of game archives and compression, encryption, obfuscation, decoding of unknown files
Dhanyel1911
Posts: 3
Joined: Wed Feb 18, 2015 1:01 am

Hyperdimension Neptunia Re Birth1 .pac file extract?

Post by Dhanyel1911 »

Well guys, I bought Hyperdimension Neptunia Re Birth1 on Steam, and wanted to help me extract the files that are in .pac format. I was looking for Hex Editor, and appeared "DW_PACK" in the file first, do not know if that helps. I want to extract the file because I intend to translate the game to the Pt-br. I would appreciate any help !!! :)

File Link:https://mega.co.nz/#!jwtGSZ5D!TPTTAyUHF86ywLVUb05A-IAU-SPbzTSnIfafFRXeD8w

NOTE: I have the translation of the game in Chinese. I uploaded it because the Chinese translation might have some in the executable script that extract the .pac file and enter the translation in. I could not extract the .exe translation, but anyone can try, as this translation translates the game to the Chinese, it can apredentar tracks. If only they can extract the translation and see their scripts, so would be easier. I hope you understand what I said above !!!

Chinese translation of the game !!! https://mega.co.nz/#!npEV3IKZ!j1zQkQv_yUMUuskLLNz6lWyAzKRn9bxjTumFv7HHqzA

Update

I decided to create this other to say I got the translation files in Chinese game. I do not know if it helps, but it should give a light. When I installed the Chinese translation in the game, the translation created a temporary folder containing all game texts and some scripts. In other words, the Chinese translation has a script that lets you open the .pac files of the game and enter the translation in, because as you can see, the translation weighs only 26MB and the game files weigh 1GB and the other weighs 60mb. I hope the help files.

Files in the temporary folder of the Chinese translation when one will need: https://mega.co.nz/#!OssiyTTK!_4OfdoSkF3nyN_brZ0BJh8lQXCqQF3k2G6fjq13EoU8

Contents of the temporary folder of the Chinese translation !!!

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Files containing the game texts !!!

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aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: Hyperdimension Neptunia Re Birth1 .pac file extract?

Post by aluigi »

chrrox
Posts: 388
Joined: Thu Aug 07, 2014 10:28 pm

Re: Hyperdimension Neptunia Re Birth1 .pac file extract?

Post by chrrox »

All they did was paste the files at the end of the archives
and update the file table to point to them.
semory
Posts: 5
Joined: Fri Aug 08, 2014 6:29 am

Re: Hyperdimension Neptunia Re Birth1 .pac file extract?

Post by semory »

Hi Luigi, chrrox and I were piddling with the hacked exe for this game and think we found the address of the function to encrypt the data. When the game loads, the first thing it does is load a file from SYSTEM00000.PAC named clear_v.cg. The data in the PAC file for this file is 0x98 bytes (including header) and 0x7C bytes not including header (The actual filesize though is 0x7B bytes, as the last byte is padding used during encryption).

As soon as this function is called, the memory address loaded in register EDX is immediately updated with the decrypted contents (see picture). The loaded content is the exact same size as the file content so we think this is encryption and not compression. But it's not just a simple XOR (the function is kind of long and calls other functions too).

If interested, could ya take a look? It would take me forever to analyze the assembly lol. I PM'd you the EXE. Base address used by OllyDbg is 0xE50000. The decryption function is at 0x010B33E0.

http://snag.gy/2czXJ.jpg

Thanks!
aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: Hyperdimension Neptunia Re Birth1 .pac file extract?

Post by aluigi »

Very interesting.
In my opinion it's a compression algorithm, for example because it uses a separate buffer for the output.
The algorithm doesn't seem complex but it's not simple how it has been implemented.
I don't know if I will work on it but I will continue to give it another test later.
sab
Posts: 1
Joined: Sun Jan 27, 2019 1:45 pm

Re: Hyperdimension Neptunia Re Birth1 .pac file extract?

Post by sab »

Help me!How open .pac file!!!