Challenge list
CryptographyLevel 2★★☆☆☆AES-ECB Mode Weakness
ECB leaks repeated block patterns. This introductory task first checks the difference between encryption and encoding.…
Digital ForensicsLevel 2★★☆☆☆Find Attack in Apache Logs
Analyze the Apache access.log (common format) to find traces of SQL injection. Tell which attacks succeeded and which…
General SkillsLevel 2★★☆☆☆Bash Scripting - Power of Automation
/app/numbers.txt contains numbers from 1 to 1000, one per line. Extract all numbers that satisfy these conditions and…
Digital ForensicsLevel 2★★☆☆☆Flag Hidden in Excel Macro
Analyze the macro code embedded in the Excel workbook and find the hidden authentication code (the flag). Learn how to…
General SkillsLevel 2★★☆☆☆Git Detective - Lost Commit
/app/repo is a Git repository. A developer accidentally deleted a commit containing important information. Use git…
General SkillsLevel 2★★☆☆☆JSON Master - Data Extraction
/app/users.json contains information of 100 users in JSON format. Extract users that meet these conditions: - age…
General SkillsLevel 2★★☆☆☆OSINT Basics - Metadata Analysis
Files recovered from a departed employee's shared drive (photos `IMG_*.jpg` and Office documents) are in…
Digital ForensicsLevel 2★★☆☆☆Hidden PDF Streams
The PDF file contains compressed object streams. An internal note that is not shown on the page is hidden inside them.…
CryptographyLevel 2★★☆☆☆RC4 Stream Cipher Weakness
RC4 was once widely used but is now deprecated. This introductory task focuses on recognizing the provided data…
CryptographyLevel 2★★☆☆☆Vigenere Cipher Decryption
Decrypt a Vigenere cipher when the key length is known and retrieve the flag. Ciphertext:…
Digital ForensicsLevel 2★★☆☆☆Find USB History in Windows Registry
Analyze the SYSTEM file (a text model of the USBSTOR part of the registry hive) to identify the USB device that was…
General SkillsLevel 2★★☆☆☆Text Processing Master - sed & awk
/app/data.csv contains CSV data. Perform these operations: 1. Extract only rows where column 2 (price) >= 1000 2.…
Digital ForensicsLevel 2★★☆☆☆Find Secret File in Disk Image
Inspect the ext4 filesystem disk image `disk.img`, find the secret backup hidden in the filesystem, and recover the…
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…
Digital ForensicsLevel 2★★☆☆☆Find Password in Packet Capture
Clear-text HTTP traffic from a shop's internal network was captured. Among many requests, exactly one is the…
CryptographyLevel 2★★☆☆☆Padding Oracle Basics
Padding oracle attacks use error differences as a plaintext recovery signal. This introductory task decodes leaked…
Digital ForensicsLevel 2★★☆☆☆Identify Intrusion Time from File Timestamps
Analyze the modification times of the files in evidence/ to identify when the intrusion occurred and which hidden…
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.…
Digital ForensicsLevel 2★★☆☆☆Find Process in Memory Dump
memory.dump is a simplified text of memory-analysis output (pslist / psscan / cmdline). Find the suspicious process…
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…