I'm looking at a binary file whose starting bytes are 0x4E 0x58 0x50. Is this an established magic number for a file format? If so, what format is it? My google-fu has proven too weak to find an answer on the intertubes.

  • Where is the file from? What application reads it? What process generated the file? How many samples do you have? If more than 1, are the values of the first 3 bytes consistent across all samples? Is the file corrupted? Is there a header structure with additional fields aside from the first 3 bytes present within the file? How do you know it is an image file? Did you use binwalk to analyze the file?
    – julian
    Commented Mar 19, 2020 at 22:20

1 Answer 1


It is a .NPK file. The full signature is NXPK.

Use the latest version of quickbms to extract the game. You can't use offzip because npk files are compressed with lz4.

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