Hex viewer and hexdump
Inspect any file byte by byte with a side-by-side hex and ASCII view, offsets, and structure highlighting.
Open in ctfpalWhen automated tools disagree or come back empty, the hexdump is the ground truth. Every other forensics tool is an interpretation of these bytes; reading them directly is how you find out which interpretation was wrong.
Reading a dump is a skill of noticing structure rather than decoding values. You are not translating bytes to meaning; you are looking for places where the texture of the data changes, because a change in texture is a boundary, and boundaries are where a challenge author put something.
What to look for
- Long runs of the same byte - padding, or a sparse region. A run of
00inside otherwise dense data often marks a boundary between concatenated files. - Structure in the ASCII column - repeated field names, dates, or paths reveal a container format even when the header is stripped.
- High entropy - dense, patternless bytes mean compression or encryption. If a region is high entropy and the rest is not, that region is the payload.
- Offsets that are round numbers - a second file starting at exactly 0x1000 or 0x10000 was appended deliberately.
Part of a module
7. File forensics and carving
Identify files by their bytes, find data appended past a format’s end marker, and pull evidence out of images and documents.
Practise on real challenges
Related tools
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Magic byte and file signature table
Look up any file format by its magic bytes, or any byte sequence by format - including the trailers that mark where a file ends.