Challenge list
CryptographyLevel 2★★☆☆☆Finding Hash Collisions
MD5 collisions are practical. Hashes with broken collision resistance must not be used for security-sensitive…
CryptographyLevel 2★★☆☆☆Hash Length Extension Attack
Simple signatures such as hash(secret || message) can be vulnerable to length extension attacks with Merkle-Damgard…
CryptographyLevel 2★★☆☆☆Padding Oracle Basics
Padding oracle attacks use error differences as a plaintext recovery signal. This introductory task decodes leaked…
ProgrammingLevel 2★★☆☆☆Programming - Bash Job Log Analysis
/challenge/jobs.log is a nightly batch log that is regenerated with random data every time the container starts. Each…
ProgrammingLevel 2★★☆☆☆Programming - PIN Brute Force
/challenge/vault.json is a vault record that is regenerated with random data every time the container starts. It…
ProgrammingLevel 2★★☆☆☆Programming - Hash Verification and Decryption
Analyze the evidence file artifact-manifest.json, which is generated randomly at every start. Each artifact…
ProgrammingLevel 2★★☆☆☆Programming - Binary TLV Parsing
/challenge/capture.bin is a custom binary file that is regenerated with random data every time the container starts.…
General SkillsLevel 2★★☆☆☆Process Hunter - Hidden Process
A process named "secret_service" is running in the background. Find this process and get the following information: 1.…
CryptographyLevel 2★★☆☆☆Rainbow Table Attack
Unsalted fast password hashes can often be reversed with precomputed lookup databases. Reverse the given MD5 hash. MD5…
General SkillsLevel 2★★☆☆☆Log Analysis - Find the Intruder
/app/auth.log contains authentication logs. Detect suspicious activity: - Identify the IP address with 10+ failed…
CryptographyLevel 2★★☆☆☆One-Time Pad Key Reuse Attack
A one-time pad is safe only when the key is used once. Reusing the key lets known plaintext recover other plaintexts.…
CryptographyLevel 2★★☆☆☆Predictable Randomness
Pseudo-random output with a fixed seed is reproducible and must not be used for cryptographic secrets. Flag generation…
General SkillsLevel 2★★☆☆☆Compression Maze - Nested Archives
/app/flag.tar.gz is a nested compressed file. Decompress step by step: flag.tar.gz → flag.tar → flag.zip.bz2.gz →…
CryptographyLevel 2★★☆☆☆Breaking Small RSA Keys
Factor a tiny RSA modulus, recover the private exponent, and decrypt a list of ciphertext values. Public key and…
CryptographyLevel 2★★☆☆☆Cryptanalysis - Breaking the Affine Cipher
ciphertext.txt is an English report encrypted with the affine cipher E(x) = (a*x + b) mod 26. Letter case is preserved…
ProgrammingLevel 2★★☆☆☆Regular Expressions - The One-Time Golden Glyph
Extract every KINO-four-digits-four-uppercase glyph from data.txt, identify the one occurring once, and submit it to…
General SkillsLevel 2★★☆☆☆Regex Master - Log File Analysis
The file /app/access.log contains thousands of access log entries. Extract all entries where the IP address starts…
General SkillsLevel 2★★☆☆☆Environment Variable Master - PATH Hijacking
There is a hidden command "getflag" in /app/secret_bin directory. However, this directory is not in PATH, so you…
General SkillsLevel 3★★★☆☆Docker Forensics - Container Investigation
With no Docker daemon available, investigate the metadata of the image `registry.internal/kinoco-billing-api:2.4.1`:…
General SkillsLevel 3★★★☆☆Find the Deleted API Key in Git History
/app/repo is a Git repository. A developer accidentally committed an API_KEY and removed it in a later commit. Inspect…
General SkillsLevel 3★★★☆☆Python Automation - REST API Data Collection
A paginated local API runs in the container at `http://127.0.0.1:8000/api/records?page=N`. Walk every page until…
ProgrammingLevel 3★★★☆☆Python Automation - SQLite Database Analysis
Examine data.db (SQLite: users / orders / audit_log), created at every start. Aggregate orders per user_id with…
ProgrammingLevel 3★★★☆☆Python Automation - Custom Cipher Decryption
cipher.txt holds the flag encrypted with a custom cipher (hex). Encryption applies per byte: add (key), xor…
ProgrammingLevel 3★★★☆☆Python Automation - Encrypted ZIP Password Cracking
A new /challenge/secret.zip is created at every start. It contains flag.txt and readme.txt, encrypted with ZipCrypto.…