Challenge list
Linux-Symlink Maze. Navigating a Branching Path
Several directories are connected in a tangled web of symbolic links. Without being misled by decoy hint files, follow…
Linux-Script Debug. Fixing a Broken Bash Script
This script has several intentional bugs (typos, syntax mistakes) and fails to run to completion. Use bash's debugging…
Linux-Network Basics. Connecting to a Listening Port
A background service on this system is listening on a specific port. Identify the port with ss/netstat and connect to…
Linux-Backup Finder. Spotting the Real Temp File
The project directory contains several decoy backup/temp files ending in .bak, .tmp, or ~. The real flag is hidden…
Linux-Pipeline. Narrowing Down Logs with grep and awk
The access log contains many entries. One IP address generated a burst of 404s, and stitching together the paths of…
Linux-Package Info. Inspecting Installed Package Details
A custom-built deb package is installed on this system. Use dpkg or apt to inspect the package's details and find…
Linux-Process Hunting. Tracking Down a Running Process
Among several background processes, one has the flag embedded in its command-line arguments. List them with ps and…
Linux-User Investigation. Filtering the Target User with awk
Several users are registered on this system. Parse /etc/passwd with awk to find the one matching a specific condition,…
Linux-Log Rotation. Searching Compressed Historical Logs
Some older log files have been gzip-compressed by log rotation. Use a command that searches inside compressed files…
Linux-Log Explorer. Digging the Flag Out of Multiple Logs
Multiple application and system log files are provided. The flag is embedded in a single DEBUG-level line — narrow it…
Linux-Environment Secrets. Finding the Variable Named FLAG
Several environment variables, including some dummy credentials, are set on this system. List them with env and find…
Hidden PDF Streams
The PDF file contains compressed object streams. An internal note that is not shown on the page is hidden inside them.…
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…
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…
Find Password in Packet Capture
Clear-text HTTP traffic from a shop's internal network was captured. Among many requests, exactly one is the…
Identify Intrusion Time from File Timestamps
Analyze the modification times of the files in evidence/ to identify when the intrusion occurred and which hidden…
Find Process in Memory Dump
memory.dump is a simplified text of memory-analysis output (pslist / psscan / cmdline). Find the suspicious process…
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…
Message Hidden in Image LSB
Extract the message hidden in the LSB (Least Significant Bit) of a PNG file. Learn the basics of steganography…
Extract Session Cookies from Chrome
You are given `/challenge/Cookies` and `/challenge/History` (both SQLite) taken from a Linux Chrome profile. The…
Detect DNS Tunneling
Analyze the DNS query log `dns_queries.log` to detect data exfiltration via DNS tunneling. Find the host flooding a…
Linux-Capabilities. Privilege Escalation Beyond SUID
A specific binary on this system has Linux capabilities assigned to it. Investigate a privilege escalation technique…
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…
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.…