About ctf-misc
A reference skill for CTF players tackling Misc challenges, covering areas such as sandbox escapes, encodings, RF/SDR, and DNS. Its decision tree and quick-reference techniques help organize an analysis path.
Key features
- 01On-demand references by challenge type
- 02Encoding and layered decoding techniques
- 03Python and Bash jail guidance
- 04RF/SDR and DNS analysis methods
- 05File identification and QR repair tips
Use cases
- 01Choose an approach for a Misc challenge
- 02Analyze restricted Python or Bash environments
- 03Work through encoding puzzles and damaged QR codes
Install
Copy the command and run it in a terminal.
$
npx skills add https:/After installing, type/ctf-miscin Claude Code to confirm it loaded.
Bundled files
References and scripts installed along with SKILL.md.
evals/evals.jsonrecall.jsonreferences/bashjails.mddns.mdencodings-advanced.mdencodings.mdgames-and-vms-2.mdgames-and-vms-3.mdgames-and-vms.mdlinux-privesc.mdpyjails.mdrf-sdr.mdDetails
From the project READMECTF 杂项挑战
深入参考
以下参考资料按需加载，根据识别出的具体方向选择对应文件：
- Python 沙箱逃逸（受限字符/func_globals链/类属性持久化） → references/pyjails.md
- Bash 沙箱/受限Shell逃逸 → references/bashjails.md
- 编码与解码（QR/esolang/Verilog/BCD/Gray码/SMS PDU） → references/encodings.md
- RF/SDR 信号处理（QAM-16/载波恢复/定时同步） → references/rf-sdr.md
- DNS 利用（ECS欺骗/NSEC遍历/IXFR/重绑定/隧道） → references/dns.md
- 游戏与VM Part1（WASM/Roblox/PyInstaller/K8s/Z3/浮点） → references/games-and-vms.md
- 游戏与VM Part2（ML权重/WebSocket/Flask/LoRA/De Bruijn） → references/games-and-vms-2.md
- 游戏与VM Part3（memfd/博弈/ROM切换/Benford/BuildKit） → references/games-and-vms-3.md
- Linux 提权（sudo通配符/NFS/SSH隧道/PostgreSQL RCE） → references/linux-privesc.md
- 高级编码（Verilog HDL/Gray码/Manchester编码/BPF字节码） → references/encodings-advanced.md
分类决策树
Misc 题目？
├─ 编码/解码谜题
│ ├─ Base64/Hex/ROT13 → CyberChef 自动检测
│ ├─ QR 码 → zbarimg / 碎片重组
│ ├─ 二进制/莫尔斯/BCD → [references/encodings.md](references/encodings.md)
│ └─ 多层嵌套 → 循环解码直到明文
├─ 沙箱逃逸
│ ├─ Python jail → [references/pyjails.md](references/pyjails.md)
│ │ ├─ 受限字符 → repunit分解 / chr()构造
│ │ ├─ 禁import → __builtins__.__import__
│ │ └─ 受限exec → func_globals链 / MRO遍历
│ └─ Bash jail → [references/bashjails.md](references/bashjails.md)
├─ 游戏/交互
│ ├─ WASM → 内存patch / wasm2wat 修改
│ ├─ WebSocket → 拦截修改消息
│ ├─ 博弈论 → Nim/承诺方案 → [references/games-and-vms-3.md](references/games-and-vms-3.md)
│ └─ ML/AI → 权重扰动 / 碰撞 → [references/games-and-vms-2.md](references/games-and-vms-2.md)
├─ DNS → [references/dns.md](references/dns.md)
├─ RF/SDR → [references/rf-sdr.md](references/rf-sdr.md)
└─ Linux 提权 → [references/linux-privesc.md](references/linux-privesc.md)
通用技巧
# 文件识别
file mystery && xxd mystery | head
binwalk -e mystery
# 编码检测
echo "data" | base64 -d
python3 -c "import base64; print(base64.b85decode(b'...'))"
# Z3 约束求解
python3 -c "
from z3 import *
x = BitVec('x', 32)
s = Solver()
s.add(x * 0x1337 == 0xdeadbeef)
s.check(); print(s.model())
"
Python Jail 速查
| 技术 | 场景 |
|---|---|
__builtins__.__import__ | import 被禁 |
().__class__.__bases__[0].__subclasses__() | 获取所有子类 |
chr() + eval() 构造 | 字符被限制 |
breakpoint() → os.system() | Python 3.7+ |
编码速查
| 编码 | 特征 |
|---|---|
| Base64 | A-Za-z0-9+/= 结尾 |
| Base32 | A-Z2-7= 大写 |
| Hex | 0-9a-f 偶数长度 |
| URL编码 | %XX 形式 |
| Unicode隐写 | 零宽字符 U+200B/U+200C |
多层编码
- 编写脚本 while 循环自动化批量解码，避免手动逐层解
QR 码修复
- 注意方向：可能需要旋转、翻转、对齐校正
- QR 有纠错/容错机制，部分损坏也能解码
Comments
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