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.
Installer avec Codex ou Claude Copiez ce prompt, collez-le dans Codex, Claude ou un autre assistant, puis laissez-le vérifier la page du skill et l'installer pour vous.
Une commande directe contourne le prompt de vérification. Examinez la source avant de l'exécuter.
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.
license
MIT
compatibility
Requires filesystem-based agent (Claude Code or similar) with bash, Python 3, and internet access for tool installation.
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
See encodings.md for Caesar brute force, URL encoding, and full details.
IEEE-754 Float Encoding (Data Hiding)
Pattern (Floating): Numbers are float32 values hiding raw bytes.
Key insight: A 32-bit float is just 4 bytes interpreted as a number. Reinterpret as raw bytes -> ASCII.
import struct
floats = [1.234e5, -3.456e-7, ...] # Whatever the challenge gives
flag = b''for f in floats:
flag += struct.pack('>f', f)
print(flag.decode())
Variations: Double '>d', little-endian '<f', mixed. See encodings.md for CyberChef recipe.
USB Mouse PCAP Reconstruction
Pattern (Hunt and Peck): USB HID mouse traffic captures on-screen keyboard typing. Use USB-Mouse-Pcap-Visualizer, extract click coordinates (falling edges), cumsum relative deltas for absolute positions, overlay on OSK image.
File Type Detection
file unknown_file
xxd unknown_file | head
binwalk unknown_file
Archive Extraction
7z x archive.7z # Universal
tar -xzf archive.tar.gz # Gzip
tar -xjf archive.tar.bz2 # Bzip2
tar -xJf archive.tar.xz # XZ
Nested Archive Script
while f=$(ls *.tar* *.gz *.bz2 *.xz *.zip *.7z 2>/dev/null|head -1) && [ -n "$f" ]; do
7z x -y "$f" && rm"$f"done
MaxiCode barcode: Hexagonal 2D barcode with bullseye center; decode with zxing (Java) since standard QR decoders fail. See encodings-advanced.md.
TOPKEK encoding: CTF-specific binary encoding where KEK=0, TOP=1, ! suffix = repeat count. See encodings-advanced.md.
See encodings.md for QR structure, repair techniques, chunk reassembly (structural and indexed-directory variants), and multi-stage URL encoding chains.
PyInstaller:pyinstxtractor.py packed.exe. See games-and-vms.md for opcode remapping.
Marshal:marshal.load(f) then dis.dis(code). See games-and-vms.md.
Python env RCE:PYTHONWARNINGS=ignore::antigravity.Foo::0 + BROWSER="cmd". See games-and-vms.md.
WASM patching:wasm2wat -> flip minimax -> wat2wasm. See games-and-vms.md.
Float precision: Large multipliers amplify FP errors into exploitable fractions. See games-and-vms.md.
K8s RBAC bypass: SA token -> impersonate -> hostPath mount -> read secrets. See games-and-vms.md.
Cookie checkpoint: Save session cookies before guesses, restore on failure to brute-force without reset. See games-and-vms-2.md.
Flask cookie game state:flask-unsign -d -c '<cookie>' decodes unsigned Flask sessions, leaking game answers. See games-and-vms-2.md.
WebSocket teleport: Modify player.x/player.y in console, call verification function. See games-and-vms-2.md.
Time-only validation: Start session, time.sleep(required_seconds), submit win. See games-and-vms-2.md.
Quine context detection: Dual-purpose quine that prints itself (passes validation) and runs payload only in server process via globals gate. See pyjails.md.
Repunit decomposition: Decompose target integer into sum of repunits (1, 11, 111, ...) using only 2 characters (1 and +) for restricted eval. See pyjails.md.
De Bruijn sequence: B(k, n) contains all k^n possible n-length strings as substrings; linearize by appending first n-1 chars. See games-and-vms-2.md.
Brainfuck instrumentation: Instrument BF interpreter to track tape cells, brute-force flag character-by-character via validation cell. See games-and-vms-2.md.
WASM memory manipulation: Patch WASM linear memory at runtime to set game state variables directly, bypassing game logic. See games-and-vms-2.md.
Lua sandbox escape: Bypass load()/os.execute() filters via os["execute"] table indexing or loadstring alias. See games-and-vms.md.
C code jail via emoji + gadget embedding: When only emoji and punctuation are allowed in C, use (😃==😃) as constant 1, build integers, embed gadgets in add eax, imm32 constants, jump to offset+1 for shellcode primitives. See games-and-vms-3.md.
Emulator ROM-switching:/load replaces ROM but preserves CPU state (registers, RAM, PC). Switch ROMs at specific PCs to combine INIT from one ROM with display instructions from another → read protected memory. See games-and-vms-3.md.
BuildKit daemon exploitation: Exposed BuildKit gRPC allows nested buildctl build with --mount=type=secret to read build secrets. Two-stage Dockerfile: install buildctl → submit nested build mounting flag secret. See games-and-vms-3.md.
Docker container escape: Privileged breakout via host device mount, docker.sock socket escape, CAP_SYS_ADMIN cgroup release_agent, container info leakage via /proc and overlayfs. See games-and-vms-3.md.
Taint analysis bypass via type coercion: In custom ML-like languages with secrecy/taint systems, if-expression secrecy depends on return type not condition — coerce side-effecting functions to private type to leak private data through public mutable refs. See games-and-vms-3.md.
Shredded document pixel-edge reassembly: Encode each strip's left/right edge as binary bitmask (dark=1), use XOR + popcount Hamming distance to greedily place strips by minimum edge distance for sub-second reassembly. See games-and-vms-3.md.
f-string config injection via stored eval: Store payload as config value, create key named eval(stored_key) — f-string rendering evaluates the key name expression, triggering RCE. See pyjails.md.
Hexadecimal Sudoku + QR assembly: 4 QR codes encode 16x16 hex Sudoku quadrants; solve grid, read diagonal as hex pairs → ASCII flag. See encodings-advanced.md.
Z3 boolean gate network SAT solving: Product key validation as 250 boolean gates (AND/OR/XOR/NOT) over 125 input bits. Model each gate as Z3 constraint, require all outputs True, solve in milliseconds. See games-and-vms.md.
3D Printer Video Nozzle Tracking (LACTF 2026)
Pattern (flag-irl): Video of 3D printer fabricating nameplate. Flag is the printed text.
Technique: Track nozzle X/Y positions from video frames, filter for print moves (top/text layer only), plot 2D histogram to reveal letter shapes:
# 1. Identify text layer frames (e.g., frames 26100-28350)# 2. Track print head X position (physical X-axis)# 3. Track bed X position (physical Y-axis from camera angle)# 4. Filter for moves with extrusion (head moving while printing)# 5. Plot as 2D scatter/histogram -> letters appear
Discord API Enumeration (0xFun 2026)
Flags hidden in Discord metadata (roles, animated emoji, embeds). Invoke /ctf-osint for Discord API enumeration technique and code (see social-media.md in ctf-osint).
SUID Binary Exploitation (0xFun 2026)
# Find SUID binaries
find / -perm -4000 2>/dev/null
# Cross-reference with GTFObins# xxd with SUID: xxd flag.txt | xxd -r# vim with SUID: vim -c ':!cat /flag.txt'
User in the docker group can mount the host filesystem into a container and chroot into it for root access.
# Check group membershipid# Look for "docker" in groups# Mount host root filesystem and chroot
docker run -v /:/mnt --rm -it alpine chroot /mnt /bin/sh
# Now running as root on the host filesystemcat /root/flag.txt
Key insight: Docker group membership is equivalent to root access. The docker CLI socket (/var/run/docker.sock) allows creating privileged containers that mount the entire host filesystem.
Sudo's fnmatch() matches * across argument boundaries. Inject extra flags (-Z root, -r, second -w) into locked-down commands. Craft pcap with embedded valid sudoers entries — sudo's parser recovers from binary junk, unlike cron's strict parser. See linux-privesc.md.
Monit Process Command-Line Injection (Zero HTB)
Root monit script uses pgrep -lfa to extract process command lines, then executes a modified version. Create fake process via perl -e '$0 = "..."' with injected flags. Apache -d last-wins overrides ServerRoot; -E captures error output. Include /root/flag causes a parse error that reveals the file content. See linux-privesc.md.
PostgreSQL RCE and File Read (Slonik HTB)
COPY (SELECT '') TO PROGRAM 'cmd' executes OS commands as postgres. pg_read_file('/path') reads files. Extract credentials from pg_basebackup archives (global/1260 = pg_authid). SSH tunnel to Unix sockets: ssh -fNL 25432:/var/run/postgresql/.s.PGSQL.5432. See linux-privesc.md.
Backup Cronjob SUID Abuse (Slonik HTB)
Root cronjob copying directories preserves SUID bit but changes ownership to root. Place SUID bash in source directory → backup copies it as root-owned SUID. Execute with bash -p. See linux-privesc.md.
PaperCut Print Deploy Privesc (Bamboo HTB)
Root process runs scripts from user-owned directory. Modify server-command, trigger via Mobility Print API refresh. See linux-privesc.md.
CTFd Platform Navigation (No Browser)
Detect CTFd (curl -s "$CTF_URL/api/v1/" | head -5) and interact via API. Ask the user for their API token (CTFd Settings > Access Tokens) — it is not provided by default. Then use Authorization: Token $CTF_TOKEN header for all requests.
# Extract hidden data from variation selectors after visible character
data = open('README.md', 'r').read().strip()
hidden = data[1:] # Skip visible emoji character
flag = ''.join(chr((ord(c) - 0xE0100) + 16) for c in hidden)
Detection: Characters appear invisible but have non-zero length. Check with [hex(ord(c)) for c in text] -- look for codepoints in 0xE0100-0xE01EF or 0xFE00-0xFE0F range.
Unicode Tags Block (U+E0000-U+E007F) (UTCTF 2026)
Pattern (Hidden in Plain Sight): Invisible Unicode Tag characters embedded in URLs, filenames, or text. Each tag codepoint maps directly to an ASCII character by subtracting 0xE0000. URL-encoded as 4-byte UTF-8 sequences (%F3%A0%81%...).
import urllib.parse
url = "https://example.com/page#Title%20%F3%A0%81%B5%F3%A0%81%B4...Visible%20Text"
decoded = urllib.parse.unquote(urllib.parse.urlparse(url).fragment)
flag = ''.join(
chr(ord(ch) - 0xE0000)
for ch in decoded
if0xE0000 <= ord(ch) <= 0xE007F
)
print(flag)
Key insight: Unicode Tags (U+E0001-U+E007F) mirror ASCII 1:1 — subtract 0xE0000 to recover the original character. They render as zero-width invisible glyphs in most fonts. Unlike Variation Selectors (U+E0100+), these have a simpler offset calculation and appear in URL fragments, challenge titles, or filenames where the text looks normal but has suspiciously long byte length.
Detection: Text or URL is longer than expected in bytes. Percent-encoded sequences starting with %F3%A0%80 or %F3%A0%81. Python: any(0xE0000 <= ord(c) <= 0xE007F for c in text).
UTF-16 Endianness Reversal
Pattern (endians): Text "turned to Japanese" -- mojibake from UTF-16 endianness mismatch.
# If encoded as UTF-16-LE but decoded as UTF-16-BE:
fixed = mojibake.encode('utf-16-be').decode('utf-16-le')
Identification: CJK characters, challenge mentions "translation" or "endian". See encodings.md for details.
Cipher Identification Workflow
ROT13 - Challenge mentions "ROT", text looks like garbled English
Base64 - A-Za-z0-9+/=, title hints "64"
Base32 - A-Z2-7= uppercase only
Atbash - Title hints (Abash/Atbash), preserves spaces, 1:1 substitution
Pigpen - Geometric symbols on grid
Keyboard Shift - Text looks like adjacent keys pressed
HISTFILE Trick for Restricted Shell File Reads (BCTF 2016)
Read files without cat/less/head: HISTFILE=/flag /bin/bash && history, or bash -v flag.txt (verbose mode prints lines), or ctypes.shdlcall for direct C library calls. See bashjails.md.
Oracle returns edit distance between guess and secret. Determine length from empty string, identify present chars from single-char repeats, binary search for positions. O(n log n) queries. See games-and-vms-3.md.
close(0x8000000000000002) passes 64-bit SECCOMP check (≠ 2) but kernel truncates to 32-bit (== 2), closing fd 2. Next open() returns fd 2 for arbitrary file. Type-width mismatch between BPF filter and kernel. See games-and-vms-3.md.
rvim Jail Escape via Python3 (BKP 2017)
rvim blocks :! but :python3 import os; os.system("cmd") executes arbitrary commands. Check :version for +python3/+lua/+ruby. See games-and-vms-3.md.
