Challenge list
CryptographyLevel 2★★☆☆☆Rainbow Table Attack
Unsalted fast password hashes can often be reversed with precomputed lookup databases. Reverse the given MD5 hash. MD5…
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…
Digital ForensicsLevel 2★★☆☆☆Recover Deleted Files
Recover the deleted compressed file (ZIP) from the disk image and find the flag in the memo inside it. Learn how to…
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…
Digital ForensicsLevel 2★★☆☆☆Message Hidden in Image LSB
Extract the message hidden in the LSB (Least Significant Bit) of a PNG file. Learn the basics of steganography…
Digital ForensicsLevel 3★★★☆☆Extract Session Cookies from Chrome
You are given `/challenge/Cookies` and `/challenge/History` (both SQLite) taken from a Linux Chrome profile. The…
Digital ForensicsLevel 3★★★☆☆Detect DNS Tunneling
Analyze the DNS query log `dns_queries.log` to detect data exfiltration via DNS tunneling. Find the host flooding a…
LinuxLevel 3★★★☆☆Linux-Capabilities. Privilege Escalation Beyond SUID
A specific binary on this system has Linux capabilities assigned to it. Investigate a privilege escalation technique…
LinuxLevel 3★★★☆☆Linux-SUID Exploit. Escalating Privileges via the find Binary
A copy of the find command with the SUID bit set exists on this system. Use a well-known GTFOBins technique to obtain…
LinuxLevel 3★★★☆☆Linux-Proc Memory. Peeking at a Process's Environment
A daemon process runs continuously in the background, with the flag set as one of its environment variables.…
LinuxLevel 3★★★☆☆Linux-Strace. Tracing System Calls to Expose a File
A binary that leaves nothing in standard output or on disk is provided. It reads a key from a hidden file,…
LinuxLevel 3★★★☆☆Linux-Race Condition. Exploiting a TOCTOU Gap for Root Files
A cleanup script that root runs periodically has a gap (TOCTOU) between checking and acting on a file. Try exploiting…
Digital ForensicsLevel 3★★★☆☆Find Deleted File Traces in NTFS $MFT
You are given `/challenge/mft_records.txt`, the `$MFT` of the Windows machine `KINOCO-WS07` written out as per-record…
Web SecurityLevel 3★★★☆☆Web-21. Blind Injection in Secure User Search
This user search app only reports whether a username exists, without showing direct query results. Investigate whether…
Web SecurityLevel 3★★★☆☆Web-22. CSP Bypass on the Secure Comment Board
This comment board is protected by a Content Security Policy restricting script execution to the site itself and a…
Web SecurityLevel 3★★★☆☆Web-23. Type Juggling in the Secure Authentication System
This login portal supports form login, a JSON API login, and a verification-code check. The admin account's real…
Web SecurityLevel 3★★★☆☆Web-24. Exploiting a Race Condition in Secure Bank
Secure Bank lets users spend a coin balance on shop prizes. If the balance check and the deduction happen as two…
Web SecurityLevel 3★★★☆☆Web-25. SSTI in the Greeting Card Generator
This greeting card generator is built with Flask/Jinja2 and renders the user's message directly through the template…
Digital ForensicsLevel 3★★★☆☆Detect Brute-Force Attack in Event Logs
Analyze the sshd authentication log `/challenge/auth.log` of the server `kinoco-srv01` and identify the session of the…
Digital ForensicsLevel 3★★★☆☆Find Suspicious Network Connections in Memory
From the memory image of the compromised host `kinoco-app03`, the socket table `/challenge/netstat_dump.txt` and the…
Digital ForensicsLevel 3★★★☆☆Recover Executed Commands from Memory
Analyze the memory-string record `memdump.txt` to recover the executed command history. Decode the Base64 strings and…
Digital ForensicsLevel 3★★★☆☆Recover Deleted SQLite Records
You are given the SQLite database `/challenge/app.db` of the internal chat tool "kinoco-msg". The body of a message…