// Provides open source intelligence techniques for CTF challenges. Use when gathering information from public sources, social media, geolocation, DNS records, username enumeration, reverse image search, Google dorking, Wayback Machine, Tor relays, FEC filings, or identifying unknown data like hashes and coordinates.
Provides AI and machine learning techniques for CTF challenges. Use when attacking ML models, crafting adversarial examples, performing model extraction, prompt injection, membership inference, training data poisoning, fine-tuning manipulation, neural network analysis, LoRA adapter exploitation, LLM jailbreaking, or solving AI-related puzzles.
Provides cryptography attack techniques for CTF challenges. Use when attacking encryption, hashing, signatures, ZKP, PRNG, or mathematical crypto problems involving RSA, AES, ECC, lattices, LWE, CVP, number theory, Coppersmith, Pollard, Wiener, padding oracle, GCM, key derivation, or stream/block cipher weaknesses.
Provides digital forensics and signal analysis techniques for CTF challenges. Use when analyzing disk images, memory dumps, event logs, network captures, cryptocurrency transactions, steganography, PDF analysis, Windows registry, Volatility, PCAP, Docker images, coredumps, side-channel power traces, DTMF audio spectrograms, packet timing analysis, CD audio disc images, or recovering deleted files and credentials.
Provides malware analysis and network traffic techniques for CTF challenges. Use when analyzing obfuscated scripts, malicious packages, custom crypto protocols, C2 traffic, PE/.NET binaries, RC4/AES encrypted communications, YARA rules, shellcode analysis, memory forensics for malware (Volatility malfind, process injection detection), anti-analysis techniques (VM/sandbox detection, timing evasion, API hashing, process injection, environment checks), or extracting malware configurations and indicators of compromise.
Provides miscellaneous CTF challenge techniques for problems that do not cleanly fit the main categories. Use for encoding puzzles, pyjails, bash jails, RF/SDR, DNS oddities, unicode tricks, esoteric languages, QR or audio puzzles, constraint solving, game theory, unusual sandbox escapes, and hybrid logic puzzles. Prefer a more specific skill first when the challenge is mainly web, pwn, reverse, forensics, malware, OSINT, or crypto. Treat this as the fallback skill for genuine cross-category or edge-case challenges, not the default starting point.
Provides binary exploitation techniques for CTF challenges. Use when you already have a vulnerable native target or service and need to turn memory corruption or low-level primitives into code execution or privilege escalation, such as buffer overflows, format strings, heap bugs, ROP, ret2libc, shellcode, kernel exploitation, seccomp bypass, sandbox escape, or Windows/Linux exploit chains. Do not use it when the main blocker is understanding what the binary does; use reverse engineering first. Do not use it for pure web bugs, disk or packet forensics, or standalone crypto/math challenges.
| name | ctf-osint |
| description | Provides open source intelligence techniques for CTF challenges. Use when gathering information from public sources, social media, geolocation, DNS records, username enumeration, reverse image search, Google dorking, Wayback Machine, Tor relays, FEC filings, or identifying unknown data like hashes and coordinates. |
| license | MIT |
| compatibility | Requires filesystem-based agent (Claude Code or similar) with bash, Python 3, and internet access for OSINT lookups. |
| allowed-tools | Bash Read Write Edit Glob Grep Task WebFetch WebSearch |
| metadata | {"user-invocable":"false"} |
Quick reference for OSINT CTF challenges. Each technique has a one-liner here; see supporting files for full details.
Python packages (all platforms):
pip install shodan Pillow
Linux (apt):
apt install whois dnsutils nmap libimage-exiftool-perl imagemagick curl
macOS (Homebrew):
brew install whois bind nmap exiftool imagemagick curl
/ctf-forensics./ctf-web./ctf-malware.# DNS recon
dig -t any target.com
dig -t txt target.com
dig axfr @ns.target.com target.com
whois target.com
# Image metadata
exiftool image.jpg
identify -verbose image.jpg | head -30
# Web archive
curl "https://web.archive.org/web/20230101*/target.com"
# Username lookup
curl -s "https://whatsmyname.app/api/lookup?username=<user>"
# Shodan
shodan search "hostname:target.com"
shodan host <ip>
https://x.com/i/user/<id> works even after renames.(id >> 22) + 1288834974657 = Unix ms.curl -sI for x-tumblr-user header. Avatar at /avatar/512. See social-media.md.XXXX+XXX (chars: 23456789CFGHJMPQRVWX). Drop a pin on Google Maps → Plus Code appears in details. Free, no API key needed. See geolocation-and-media.md.exiftool image.jpg # EXIF data
pdfinfo document.pdf # PDF metadata
mediainfo video.mp4 # Video metadata
site:example.com filetype:pdf
intitle:"index of" password
Image TBS filters: Append &tbs=itp:face to Google Image URLs to filter for faces only (strips logos/banners). See web-and-dns.md.
/export?format=csv, /pub, /gviz/tq?tqx=out:csv, /htmlview. See web-and-dns.md.dig -t txt subdomain.ctf.domain.com
dig axfr @ns.domain.com domain.com # Zone transfer
Always check TXT, CNAME, MX for CTF domains. See web-and-dns.md.
https://metrics.torproject.org/rs.html#simple/<FINGERPRINT> -- check family, sort by "first seen". See web-and-dns.md.gh api. See web-and-dns.md./start, answer verification questions. See web-and-dns.md.curl "http://ip-api.com/json/103.150.68.150"
Pattern: Visually-identical Unicode characters from different blocks (Cyrillic, Greek, Math) encode binary data in social media posts. ASCII = 0, homoglyph = 1. Group bits into bytes for flag. See social-media.md.
No auth needed. Endpoints: public.api.bsky.app/xrpc/app.bsky.feed.searchPosts?q=..., app.bsky.actor.searchActors, app.bsky.feed.getAuthorFeed. Check all replies to official posts. See social-media.md.
Pattern: Port appears open on a standard service port (22/SSH, 80/HTTP) but runs a fake service. nmap -sV or nc host port reveals the flag in the banner. Never trust port numbers alone -- always fingerprint the service. See web-and-dns.md.
Search Shodan by SSH host key fingerprint to identify servers: shodan search "fingerprint:AA:BB:CC:...". See web-and-dns.md.
Lookup usernames across gaming platforms (Steam, Xbox, PSN, MMOs) for character profiles, activity, and linked accounts. See social-media.md.