Challenge list
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…
Git Detective - Lost Commit
/app/repo is a Git repository. A developer accidentally deleted a commit containing important information. Use git…
JSON Master - Data Extraction
/app/users.json contains information of 100 users in JSON format. Extract users that meet these conditions: - age…
Linux-02. Privilege Escalation via a Sudo-Allowed Vim
Check which commands a regular user can run via sudo without a password. A well-known GTFOBins technique can let you…
Linux-03. Reading Cron Configuration Files
This system has several cron configurations (/etc/cron.d, /etc/crontab, user crontabs, and more). Inspect each…
Linux-Cron Privesc. Hijacking a Writable Root Script
Check the permissions of a cron script that root executes periodically. If a regular user can write to it, think about…
Linux-Systemd. Checking a Service Unit's Environment Variable
A systemd unit file can set environment variables in its [Service] section. Inspect the registered service definition…
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…
OSINT Basics - Metadata Analysis
Files recovered from a departed employee's shared drive (photos `IMG_*.jpg` and Office documents) are in…
Text Processing Master - sed & awk
/app/data.csv contains CSV data. Perform these operations: 1. Extract only rows where column 2 (price) >= 1000 2.…
Network Analysis - DNS Zone Transfer Leak
An unauthenticated DNS zone transfer (AXFR) against a misconfigured authoritative server was captured. Download the…
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 Analysis - SMB Share Enumeration Leak
An attacker enumerating SMB shares on the network was captured. Download the packet capture (traffic.pcap), follow the…
Network Analysis - Telnet Credentials
A legacy server was administered over Telnet in clear text. Download the packet capture (traffic.pcap), follow the…