competition-crypto-mobile

A specialist workflow for capture-the-flag challenges involving cryptography, hidden data, mobile apps, and encoded files. It is designed to run after a separate CTF sandbox setup.

In plain words
What is it for?
Use it to reconstruct encoding or encryption steps, extract hidden media data, inspect APK or IPA behavior, and reproduce accepted mobile or cryptographic results.
Why use it?
It provides little standalone value without that preceding sandbox workflow and its assumptions about the challenge environment.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/2233admin/reverse-skill-evolver/competition-crypto-mobile
Any agent
npx skills add 2233admin/reverse-skill-evolver --skill competition-crypto-mobile
Clone the repo
git clone --depth 1 https://github.com/2233admin/reverse-skill-evolver

Made for: Claude Code, Codex.

Per session 105 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 607 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00105 $0.00607
Opus 5 $0.00053 $0.00303
Sonnet 5 $0.00021 $0.00121
Haiku 4.5 $0.00011 $0.00061

Measured 3d ago against content hash 7d78f7d1dc17, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

competition-crypto-mobile scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

100% identical to competition-crypto-mobile — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

CTF-Sandbox-Orchestrator/competition-crypto-mobile/SKILL.md · 51 lines

How it starts

The opening of the file, as written. The whole thing — 51 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Competition Crypto Mobile

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 active challenge depends on recovering a transform chain, hidden media payload, mobile signing path, or local trust boundary.

Reply in Simplified Chinese unless the user explicitly requests English.

Quick Start

  1. Decide whether the dominant path is crypto, stego, or mobile.
  2. Recover transforms in order; do not jump straight to the fanciest algorithm.
  3. Record exact parameters and boundaries that affect the result.
  4. Hook the narrowest mobile boundary that proves the behavior.
  5. Reproduce the plaintext, payload, signed request, or accepted branch.

Workflow

1. Crypto And Encoding

  • Reconstruct the chain step by step: container, compression, encoding, xor or substitution, crypto, integrity, final parse.
  • Keep exact keys, IVs, nonces, salts, tags, offsets, and byte order.

2. Stego

  • Inspect metadata, chunk layout, palettes, alpha planes, LSBs, thumbnails, trailers, and transcoding artifacts.
  • Rank decode attempts by evidence, not by brute-force curiosity.

3. Mobile

  • Start with manifest or plist, exported components, deeplinks, native libs, shared prefs, local DBs, and configs.
  • Trace signer logic, token storage, SSL pinning, protobuf or RPC boundaries, and native bridge calls.

Read This Reference

  • Load references/crypto-mobile.md for the transform checklist, hook targets, and evidence packaging.
  • If the task is specifically about Android dynamic tracing, signer hooks, JNI boundaries, or pinning checks, prefer $competition-android-hooking.
  • If the task is specifically about iOS runtime tracing, Keychain access, Objective-C or Swift hooks, or pinning checks inside an IPA, prefer $competition-ios-runtime.
  • If the task is specifically about media carriers, hidden channels, thumbnails, or appended trailers, prefer $competition-stego-media.

Read the full file on GitHub · 51 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 51 lines · 105 tokens per session scan A 7d78f7d1dc17

Subscribe to this mod's changes

competition-crypto-mobile is a skill published in the GitHub repository 2233admin/reverse-skill-evolver (13 stars, last pushed 22d ago), licensed MIT. It adds 105 tokens to every session and 607 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to competition-crypto-mobile, differing in 0 lines, and is treated as a copy.

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