.npk Game Files detecting EXPK not NXPK

Extraction and unpacking of game archives and compression, encryption, obfuscation, decoding of unknown files
godskin
Posts: 192
Joined: Sun Oct 04, 2015 2:27 am

[ Android ] MARVEL Super War ( .npk)

Post by godskin »

crackofdawn
Posts: 3
Joined: Tue May 28, 2019 3:24 pm

.npk Game Files detecting EXPK not NXPK

Post by crackofdawn »

Hi all!

Pretty new to this world, but I've spent some time familiarizing myself with the quickbms tool and its script. I tried running the nxpk.bms script on a set of .npk files and I'm getting the following error:

"Signature of 4 bytes at offset 0x00000000 doesn't match the one expected by the script:
this one: "EXPK"
45 58 50 4b EXPK
expected: "NXPK"
4e 58 50 4b NXPK

- 0 files found in 0 seconds
coverage file 0 0% 4 38568664 . offset 00000004"

It seems like encryption is off by one digit (5 vs e). I was wondering if there was anything that could be done to get around this encryption? Any guidance would be much appreciated.

I've attached one of the smaller files of the bunch. I had to add it to a .rar since .npk files cannot be uploaded here.


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

Re: .npk Game Files detecting EXPK not NXPK

Post by aluigi »

I suspect it's some sort of compression because the 32bit field at offset 0x14 looks like a decompressed size.
The data is 0x370354 bytes while that field is 0x370194, additionally the consecutive zeroes at the end of the data don't match with a possible encryption since it should be just garbage.

Currently I don't know what compression algorithm it may be.
crackofdawn
Posts: 3
Joined: Tue May 28, 2019 3:24 pm

Re: .npk Game Files detecting EXPK not NXPK

Post by crackofdawn »

Thanks for giving it a go! It's a game that just came out, maybe it's some fancy new algorithm! Who am I kidding, I don't know anything about this stuff ^.^ Have a great week!
aluigi
Site Admin
Posts: 12984
Joined: Wed Jul 30, 2014 9:32 pm

Re: .npk Game Files detecting EXPK not NXPK

Post by aluigi »

@godskin
I have merged your previous topic in this one because this is another EXPK format.
I preferred to keep them in the same topic.