Challenge list
CryptographyLevel 1★☆☆☆☆02. Hidden Secret - Base64 Decode
Base64 is an encoding method used to transmit binary data as text. It's not encryption, but it's often used for…
Network SecurityLevel 1★☆☆☆☆08. Network Basics - Learn Port Numbers
Networks use port numbers to identify services. For example, a web server (HTTP) usually uses port 80, and encrypted…
CryptographyLevel 1★☆☆☆☆11. Decode the Caesar Cipher
The Caesar cipher is one of the oldest classical ciphers used by Julius Caesar. It encrypts by shifting alphabet…
Digital ForensicsLevel 1★☆☆☆☆12. Identify File Signatures
Files contain identification information called "magic bytes" at the beginning. Even if the extension is disguised,…
Digital ForensicsLevel 1★☆☆☆☆13. Hidden Metadata in Images
Photos and images contain metadata called EXIF. This metadata records shooting date, camera info, GPS coordinates,…
CryptographyLevel 1★☆☆☆☆14. ROT13 Magic
ROT13 (Rotate 13) is a type of Caesar cipher that shifts the alphabet by 13 letters. Interesting feature of ROT13:…
Digital ForensicsLevel 1★☆☆☆☆15. Extract Strings from Binary
Binary files (executables, etc.) contain human-readable strings. Passwords, URLs, error messages, and other hints can…
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…
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…
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…
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…
Network SecurityLevel 2★★☆☆☆Network Analysis - DNS Zone Transfer Leak
An unauthenticated DNS zone transfer (AXFR) against a misconfigured authoritative server was captured. Download the…
Network SecurityLevel 2★★☆☆☆Network Analysis - ICMP Data Exfiltration
Data was exfiltrated from the internal host 10.20.0.15 to the external host 203.0.113.66 disguised as ping (ICMP echo…
Network SecurityLevel 2★★☆☆☆Network Analysis - SMB Share Enumeration Leak
An attacker enumerating SMB shares on the network was captured. Download the packet capture (traffic.pcap), follow the…
Network SecurityLevel 2★★☆☆☆Network Analysis - Telnet Credentials
A legacy server was administered over Telnet in clear text. Download the packet capture (traffic.pcap), follow the…
Network SecurityLevel 2★★☆☆☆Network Analysis - Anonymous FTP Transfer
An anonymous FTP session was captured in clear text. Download the packet capture (traffic.pcap), follow the FTP data…
Network SecurityLevel 2★★☆☆☆Network Analysis - Clear-text HTTP Credentials
Analyze traffic intercepted on public Wi-Fi where someone logged in over plain HTTP. Download the packet capture…
Network SecurityLevel 2★★☆☆☆Network Analysis - Plaintext SMTP Attachment
The internal host 10.30.0.25 sent an email to port 25 of the mail server 10.30.0.10 without encryption. Download…
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…