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

Esoteric Language Detection

Team Roles

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

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