Agent Skills
› zhaoxuya520/reverse-skill
› competition-stego-media
competition-stego-media
GitHubCTF隐写分析专用技能，用于从图像、音频、视频等媒体中提取隐藏载荷。通过检查元数据、LSB、通道及尾随数据还原信息，需在沙箱环境确认后使用。
Trigger Scenarios
用户要求检查媒体文件的元数据、Alpha/调色板通道、LSB或缩略图
需要从媒体中恢复隐藏载荷而不进行盲目暴力破解
CTF挑战涉及媒体容器内的隐写或附加载荷
Install
npx skills add zhaoxuya520/reverse-skill --skill competition-stego-media -g -y
SKILL.md
Frontmatter
{
"name": "competition-stego-media",
"description": "Internal downstream skill for ctf-sandbox-orchestrator. CTF-sandbox workflow for image, audio, video, document, and container steganography. Use when the user asks to inspect metadata, alpha or palette channels, LSBs, thumbnails, appended trailers, QR fragments, transcoding artifacts, or recover a hidden payload from media without blind brute force. Use only after `$ctf-sandbox-orchestrator` has already established sandbox assumptions and routed here."
}
Competition Stego Media
Use this skill only as a downstream specialization after $ctf-sandbox-orchestrator is already active and has established sandbox assumptions, node ownership, and evidence priorities. If that has not happened yet, return to $ctf-sandbox-orchestrator first.
Use this skill when the challenge lives inside a media container, hidden channel, or appended payload rather than a conventional crypto blob.
Reply in Simplified Chinese unless the user explicitly requests English.
Quick Start
- Confirm the real container type, dimensions, duration, codec, and chunk layout before guessing a hidden layer.
- Check metadata, thumbnails, sidecar files, and appended trailers before deeper signal-domain work.
- Rank candidate channels by evidence: alpha, palette, LSB, transform-domain residue, frame order, or container slack.
- Preserve each extracted layer separately so the transform chain stays reproducible.
- Stop when the hidden payload is reproduced, not merely suspected.
Workflow
1. Establish Container Truth
- Inspect headers, chunk tables, EXIF or document metadata, container indexes, thumbnails, and file size anomalies.
- Compare declared format against observed structure to catch polyglots, appended archives, or malformed trailers.
- Record exact offsets, frame numbers, or channel boundaries that look promising.
2. Inspect Candidate Channels
- Check alpha, palette order, RGB or YUV planes, LSBs, spectrogram features, document object streams, or video frame deltas.
- Prefer evidence-driven attempts over brute forcing every transform.
- Note whether the payload is plain bytes, another media layer, compressed data, or an encrypted blob.
3. Reconstruct The Hidden Payload Path
- Keep the chain in order: container -> channel or carrier -> extraction -> decompression or decode -> final parse.
- Separate extraction success from final interpretation; a channel hit is not the same as artifact recovery.
- If the problem becomes primarily about cryptography after extraction, hand off to the broader crypto skill.
Read This Reference
- Load
references/stego-media.mdfor the media checklist, channel ranking guide, and evidence packaging.
What To Preserve
- File structure facts: offsets, chunks, frame numbers, stream names, metadata keys, and trailer size
- Intermediate extractions and the exact command or transform used to produce them
- The final recovered payload and the channel that produced it
Version History
- 1bec1f2 Current 2026-07-05 18:46
