ctf-skills is a collection of agent instructions for solving capture-the-flag security challenges, including web exploitation, binary vulnerabilities, cryptography, reverse engineering, forensics, and OSINT. It is intended for agents and people working through CTF problems, and its skills can be loaded into supported coding-agent workflows.
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.
npx skills add ljagiello/ctf-skills --skill ctf-miscgit clone --depth 1 https://github.com/ljagiello/ctf-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/ljagiello/ctf-skills/ctf-misc)<a href="https://agentmods.dev/skills/ljagiello/ctf-skills/ctf-misc"><img src="https://agentmods.dev/badge/skills/ljagiello/ctf-skills/ctf-misc/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/ljagiello/ctf-skills/ctf-misc"><img src="https://agentmods.dev/badge/skills/ljagiello/ctf-skills/ctf-misc.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket warn
- Snyk fail
- NVIDIA SkillSpector warn
SkillSpector: 14 findings, up to high
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- high YARA Match · line 190 YARA rule matched a hack tool or exploit indicator (offensive tools, reconnaissance, privilege escalation, or exploit frameworks).Fix: Remove offensive tool references and exploit code. Legitimate agent skills should not contain penetration testing tools, exploit frameworks, or reconnaissance utilities.
- high System Prompt Leakage · line 251 Skill contains instructions that could directly expose system prompts, internal rules, or hidden instructions to users or external parties.Fix: Remove any instructions that reveal, print, or output system prompts or internal rules. System instructions should never be exposed to end users.
- high YARA Match · line 283 YARA rule matched a hack tool or exploit indicator (offensive tools, reconnaissance, privilege escalation, or exploit frameworks).Fix: Remove offensive tool references and exploit code. Legitimate agent skills should not contain penetration testing tools, exploit frameworks, or reconnaissance utilities.
- high Privilege Escalation · line 298 Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
- high Privilege Escalation · line 307 Potential security issue detected. Manual review is recommended.Fix: Review the flagged content for security risks. Ensure no credentials, secrets, or sensitive data are exposed.
- high Privilege Escalation · line 319 Potential security issue detected. Manual review is recommended.Fix: Review the flagged content for security risks. Ensure no credentials, secrets, or sensitive data are exposed.
- high Privilege Escalation · line 325 Potential security issue detected. Manual review is recommended.Fix: Review the flagged content for security risks. Ensure no credentials, secrets, or sensitive data are exposed.
- high Privilege Escalation · line 353 Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
- medium Privilege Escalation · line 47 Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
- medium Privilege Escalation · line 303 Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
- medium Privilege Escalation · line 329 Commands invoke sudo or root privileges. Verify this elevated access is necessary and justified.Fix: Avoid sudo/root unless strictly required. Prefer least-privilege patterns. If elevation is needed, document the justification and scope.
- medium MCP Rug Pull · line 307 Docker image references without a specific tag (:latest is implicit) or digest (@sha256:...) can be silently replaced by a malicious image.Fix: Pin the image: image:tag or image@sha256:abc123
- medium MCP Rug Pull · line 319 Docker image references without a specific tag (:latest is implicit) or digest (@sha256:...) can be silently replaced by a malicious image.Fix: Pin the image: image:tag or image@sha256:abc123
- medium Data Exfiltration · line 358 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00122 | $0.07196 |
| Opus 5 | $0.00061 | $0.03598 |
| Sonnet 5 | $0.00024 | $0.01439 |
| Haiku 4.5 | $0.00012 | $0.00720 |
Grade A, and why
ctf-misc 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 11d 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.
Copies of this mod
3 near-identical copies found in the catalogue:
- ctf-misc — 100% identical, 0 lines differ
- fieldops-ctf-misc — 95% identical, 31 lines differ
- ctf-misc — 92% identical, 116 lines differ
How it starts
The opening of the file, as written. The whole thing — 497 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CTF Miscellaneous
Quick reference for miscellaneous CTF challenges. Each technique has a one-liner here; see supporting files for full details.
Prerequisites
Python packages (all platforms):
pip install z3-solver pwntools Pillow numpy requests dnslib
Linux (apt):
apt install ffmpeg qrencode
macOS (Homebrew):
brew install ffmpeg qrencode
Manual install:
- SageMath — Linux:
apt install sagemath, macOS:brew install --cask sage
Additional Resources
- pyjails.md - Python jail/sandbox escape techniques, quine context detection, restricted character repunit decomposition, func_globals module chain traversal, restricted charset number generation, class attribute persistence, f-string config injection via stored eval
- bashjails.md - Bash jail/restricted shell escape techniques, HISTFILE file read trick, bash -v verbose mode, ctypes.sh direct C library calls
- encodings.md - Encodings, QR codes, esolangs, UTF-16 tricks, BCD encoding, multi-layer auto-decoding, indexed directory QR reassembly, multi-stage URL encoding chains
- encodings-advanced.md - Verilog/HDL, Gray code cyclic encoding, RTF custom tag extraction, SMS PDU decoding, multi-encoding sequential solvers, UTF-9, pixel binary encoding, hexadecimal Sudoku + QR assembly, TOPKEK, MaxiCode
- rf-sdr.md - RF/SDR/IQ signal processing (QAM-16, carrier recovery, timing sync)
- dns.md - DNS exploitation (ECS spoofing, NSEC walking, IXFR, rebinding, tunneling)
- games-and-vms.md - WASM patching, Roblox place file reversing, PyInstaller, marshal analysis, Python env RCE, Z3 (including boolean logic gate network SAT solving), K8s RBAC, floating-point precision exploitation, custom assembly language sandbox escape via Python MRO chain
- games-and-vms-2.md - Cookie checkpoint game brute-forcing, Flask cookie game state leakage, WebSocket game manipulation, server time-only validation bypass, De Bruijn sequence, Brainfuck instrumentation, WASM linear memory manipulation
- games-and-vms-3.md - memfd_create packed binaries, multi-phase crypto games with HMAC commitment-reveal and GF(256) Nim, emulator ROM-switching state preservation, Python marshal code injection, Benford's Law bypass, parallel connection oracle relay, nonogram solver pipelines, 100 prisoners problem, C code jail escape via emoji identifiers, BuildKit daemon build secret exploitation, Docker container escape, Levenshtein distance oracle attack, taint analysis bypass via type coercion, shredded document pixel-edge reassembly
- games-and-vms-4.md - Part 4 (2018-era): XSLT as Turing-complete VM, JavaScript MAX_SAFE_INTEGER successor equality, binary search oracle in comparison-only DSL, blind SQLi via script-engine timeout error, OEIS sequence lookup automation, QR code reassembly from format-string constraints, matrix exponentiation for Fibonacci recurrence, Tribonacci for frog-jump counting, Selenium + Tesseract dynamic CAPTCHA, Brainfuck→Piet multi-layer polyglot, bytebeat synth code recognition
- linux-privesc.md - Sudo wildcard parameter injection (fnmatch), crafted pcap for sudoers.d, monit confcheck process injection, Apache -d override, backup cronjob SUID, PostgreSQL COPY TO PROGRAM RCE, PostgreSQL backup credential extraction, NFS share exploitation, SSH Unix socket tunneling, PaperCut Print Deploy privesc, Squid proxy pivoting, Zabbix admin password reset via MySQL, WinSSHTerm credential decryption
- ctfd-navigation.md - CTFd platform API navigation without browser: detection, token auth, challenge listing, file download, flag submission, scoreboard, hints, notifications, Python client class
What ships with it
12 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.
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.
- 11d ago First seen · 497 lines · 122 tokens per session scan F 7c93032c00d9
ctf-misc is a skill published in the GitHub repository ljagiello/ctf-skills (3,234 stars, last pushed 16d ago), licensed MIT. It adds 122 tokens to every session and 7,196 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
respond-to-eval
Turn student course evaluations (free-text + numeric) into an actionable teaching-improvement plan — the teaching analogue of /respond-to-referees. Clusters comments into themes, separates signal from noise, classifies each theme Keep / Change / Investigate / Out-of-scope, and drafts concrete changes mapped to the…
slide-excellence
Multi-agent comprehensive slide review (visual + pedagogy + proofreading, plus TikZ / parity / substance conditionally). Use when user says "full review", "excellence pass", "comprehensive check", "review everything", "pre-release review", "slide excellence", or before teaching / shipping a deck. Fanout wrapper — for…
scaffold-exercises
Scaffold a graded problem set with sections, problems, worked solutions, and short "why this matters" explainers across analytical, empirical, and coding types. Use when user says "make a problem set on X", "scaffold exercises for this lecture", "create practice problems", "generate homework with a solution key"…
syllabus
Build or restructure a course syllabus from a topic list or reading list — course description + prerequisites, week-by-week schedule (topic → readings → deliverables), measurable learning objectives, an assessment scheme + rubric, standard policies (late work, AI use, academic integrity, accessibility), and a per-week…
teach-from-paper
Turn a research paper into teaching materials — a lecture outline, the 3-5 results worth presenting (with intuition), a slide skeleton ready for /create-lecture, discussion questions, and a problem-set brief. Reads the paper end-to-end and pitches to a stated audience level. Use when user says "turn this paper into a…
create-lecture
Create a new Beamer lecture .tex from source papers and materials, with notation consistency checks and the project's preamble wired in. Use when user says "create a lecture on X", "new lecture from these papers", "start a deck on topic Y", "scaffold a new Beamer file", "build me a lecture from these PDFs". Scaffolds…