Challenge list
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…
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…
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…
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…
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 →…