What you will learn
- Use essential CTF tools
- Develop a methodical observation habit
- Build foundations for specialist categories
Beginner CTF and Security Fundamentals
Build the command-line, encoding, search, and tool skills needed before moving into specialist security topics.
General Skills challenges
42 challenges available.
General SkillsLevel 1★☆☆☆☆01. First Steps - Binary and Hexadecimal
In the security world, binary and hexadecimal are commonly used. In this challenge, convert hexadecimal to ASCII…
General SkillsLevel 1★☆☆☆☆10. Security Basics - Ethics and Rules
To become a white hat hacker, knowledge of ethics and laws is just as important as technical skills. In this…
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…
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…
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.…
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.…
General SkillsLevel 2★★☆☆☆Log Analysis - Find the Intruder
/app/auth.log contains authentication logs. Detect suspicious activity: - Identify the IP address with 10+ failed…
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 →…
General SkillsLevel 2★★☆☆☆Regex Master - Log File Analysis
The file /app/access.log contains thousands of access log entries. Extract all entries where the IP address starts…
General SkillsLevel 2★★☆☆☆Environment Variable Master - PATH Hijacking
There is a hidden command "getflag" in /app/secret_bin directory. However, this directory is not in PATH, so you…
General SkillsLevel 3★★★☆☆Docker Forensics - Container Investigation
With no Docker daemon available, investigate the metadata of the image `registry.internal/kinoco-billing-api:2.4.1`:…
General SkillsLevel 3★★★☆☆Find the Deleted API Key in Git History
/app/repo is a Git repository. A developer accidentally committed an API_KEY and removed it in a later commit. Inspect…
General SkillsLevel 3★★★☆☆Python Automation - REST API Data Collection
A paginated local API runs in the container at `http://127.0.0.1:8000/api/records?page=N`. Walk every page until…
General SkillsLevel 3★★★☆☆SQL Query Master - Complex Joins
The SQLite database `/challenge/company.db` has 3 tables: - employees (id, name, department_id, salary, email, note) -…
General SkillsLevel 3★★★☆☆System Call Tracing - strace Debugging
Analyze `/challenge/strace.log`, a strace recording of the source-less program `/app/mystery_program`. The program…
General SkillsLevel 3★★★☆☆System Log Analysis - journalctl Master
Analyze `/challenge/system.log`, a systemd journal exported in `journalctl -o short` style. Each line reads "timestamp…
General SkillsLevel 3★★★☆☆Network Master - Netcat Reverse Shell
Analyze the prerecorded artifacts/netcat/callback-transcript.log without connecting to any external host; no listener…
General SkillsLevel 3★★★☆☆Performance Analysis - Find the Resource Hog
Analyze the server snapshot `/challenge/metrics.log`. The first half is a top-style process table (%CPU is column 9,…
General SkillsLevel 3★★★☆☆Regex Expert - Data Validation
/challenge/data.txt holds 400 contact records. Each line contains an email address, a phone number, an IP address and…
General SkillsLevel 3★★★☆☆Advanced Automation - Directory Monitor
`/challenge/logs/` holds access logs from four web front ends (combined log format, 60 files, over 100k lines). The…
General SkillsLevel 4★★★★☆AWS CLI - S3 Bucket Investigation
An offline export of the S3 configuration is under `/challenge/s3_audit/` (`buckets.json` plus each bucket's…
General SkillsLevel 4★★★★☆Ansible Automation - Server Configuration Management
Analyze the generated run export artifacts/ansible/vault-export.yml without running Ansible or touching a server. It…