misc

CTF Misc

Analyze and solve miscellaneous challenges.

When to Use

Use this command for challenges involving:

• Encoding chains
• Esoteric programming languages
• QR codes and barcodes
• Logic puzzles
• Challenges that don't fit other categories

Bundled Scripts

• check-tools.sh — Verify required misc tools are installed
• run-decode.sh — Multi-encoding decoder: tries Base64, Base32, hex, ROT13, URL, binary. Detects encoding type, attempts recursive decoding chains, and searches for flags. Outputs JSON with all decoded results.

Instructions

1. First check tool availability: bash scripts/check-tools.sh

2. For encoding detection and decoding (outputs structured JSON):

   bash scripts/run-decode.sh <encoded-string>
   bash scripts/run-decode.sh encoded.txt
   

   JSON output includes:

   • detected_encoding: what the input looks like (base64, hex, binary, etc.)
   • decodings[]: all successful decodings with confidence levels
   • chains[]: multi-step decoding results (e.g., base64 → hex → plaintext)
   • flags: any flag patterns found in decoded output
   • has_flag: true if flag found

   The script automatically tries chaining: if Base64 decoding produces another encoded string, it tries decoding that too.

3. For QR codes:

   zbarimg qrcode.png
   

4. For esoteric languages:

   • Brainfuck: ++++[>++++++++<-]>.
   • Ook!: Ook. Ook! Ook.
   • Whitespace: Only spaces, tabs, newlines
   • JSFuck: []!+() characters only

   Use online interpreters for these.

Encoding Chain Workflow

The run-decode.sh script handles multi-step chains automatically:

1. Input → detect encoding type
2. Try all standard decodings (base64, hex, ROT13, URL, binary)
3. For each successful decoding → try decoding the result again
4. Search all intermediate and final results for flag patterns
5. Output unified JSON with all results

Common Encoding Patterns

Pattern	Encoding
= or == at end	Base64
All caps + 2-7	Base32
Only 0-9 a-f	Hexadecimal
Only 0 and 1	Binary
%20, %3D	URL encoding
A, A	HTML entities

Esoteric Language Detection

Looks Like	Language
+ - < > [ ] . ,	Brainfuck
Ook. Ook! Ook?	Ook!
Only whitespace	Whitespace
[]+!()	JSFuck
moo, MOO	COW

Team Roles

When using /ctf-kit:team-solve with a misc challenge, the lead spawns 3 specialists:

Role	Teammate Name	Focus	Tools	First Action
Encoding Specialist	decoder	CyberChef recipes, multi-layer encoding chains, base conversions, custom encodings, cipher identification	CyberChef, scripts/run-decode.sh, python3	Run run-decode.sh, try recursive decoding, identify encoding layers
Esoteric & Code	esoteric-analyst	Brainfuck, Whitespace, JSFuck, Ook!, Malbolge, polyglots, custom language identification	Online interpreters, python3	Identify language from character set, find/build interpreter, execute
Puzzle & Logic	puzzle-solver	Pattern recognition, math puzzles, QR/barcodes, game theory, constraint satisfaction, riddles	zbarimg, python3, z3	Scan for QR/barcodes, analyze patterns, identify puzzle type

When to broadcast

• Decoder: "Base64 decoded to hex, hex decoded to... another encoding" — puzzle solver helps identify the pattern
• Esoteric: "Identified as Whitespace language, output is: PARTIAL_STRING" — decoder checks if output needs further decoding
• Puzzle: "QR code contains URL / encoded string" — decoder processes the content
• Any: "Found the flag" — immediate broadcast, all stop

Example Usage

/ctf-kit:misc encoded.txt
/ctf-kit:misc qrcode.png
/ctf-kit:misc challenge.bf