# Zsteg

> Auth/lab ref: zsteg PNG/BMP steganography; LSB, bit-plane, color-channel, hidden-data extraction after metadata/strings checks.

- Skill: `aeondave/zsteg` (Agent Skill)
- Install (CLI): `npx skillmds@latest add aeondave/zsteg`
- Raw SKILL.md: https://api.skillmd.com/api/skills/aeondave/zsteg/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: AeonDave (https://skillmd.com/u/aeondave)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/aeondave/zsteg

---


# zsteg

Bit-plane spelunking for images that are too quiet on the surface.

## When to use zsteg

Use zsteg when you need to:

- scan PNG/BMP files for common LSB and channel-hiding tricks
- enumerate embedded payload candidates quickly
- extract a promising payload for deeper analysis

## Quick Start

```bash
# Automatic scan
zsteg -a image.png

# Default inspection
zsteg image.png
```

## High-Value Workflows

### Extract a specific candidate

```bash
zsteg -E "b1,r,lsb,xy" image.png > payload.bin
```

### Broad PNG/BMP triage

1. Run `zsteg -a`.
2. Review human-readable hits first.
3. Extract promising payloads with `-E`.
4. Feed extracted bytes into `file`, `strings`, `foremost`, or archive tools.

## Practical Notes

- zsteg shines on PNG/BMP artifacts; JPEG-focused suspects usually belong to other workflows.
- Not every hit is meaningful; short text fragments and compressed junk both show up.
- Pair with `steghide`, `stegseek`, and normal image triage rather than betting everything on one pass.

## Caveats

- False positives are common on busy or large images.
- The interesting payload may need decompression or decoding after extraction.
- Channel/bit-order choice matters; extraction without context can mislead.

## Resources

No bundled `scripts/`, `references/`, or `assets/`.
Use the upstream README for extractor spec syntax and advanced scan flags.