First steps in the shell
Get comfortable with the command line. Explore the filesystem and find the flag hidden in one of the folders.
Lab 1 of 9 in the Linux Fundamentals path. If you get stuck you have 2 hints, from the vaguest to the most precise: they cost 0 and 30 XP.
What you learn
Objectives complete themselves while you work in the terminal; each one is worth experience points:
- Read the README (50 XP)
- Find the hidden flag (150 XP)
Topics: linux, basics.
Commands you will use
The terminal is simulated and understands about forty Linux commands. In this lab you will mostly need these:
ls: lists the files in a folder; with -l it shows permissions and owners, with -a hidden files too. It is the first command on any machine.cat: prints the contents of a file: the most direct way to read configurations, notes and logs.cd: changes folder, with an absolute path (starting from /) or a relative one (with . and ..).
The simulated environment
You work in a simulated Linux shell, in the home folder of the user runner: invented files and folders, no network target.
The defensive lesson
Once the lab is solved, the write-up explains what went wrong and how to protect yourself:
The shell is your main tool. ls/cd/cat let you navigate any machine. Looking into "secret", "backup" and "config" folders is the first reflex of any recon.
Before and after this lab
It is a starting point: no other lab is required.
After this lab you can move on to:
- Where am I? Absolute and relative paths (Linux Fundamentals, easy)
The Linux Fundamentals path
Linux Fundamentals is the starting point. Almost every server, network device and security tool runs on Linux, and anyone who defends a system (or tests it with permission) spends much of their time in a terminal. Here you learn to move around the filesystem, find hidden files, read huge logs piece by piece, search for words with grep, chain commands with pipes and understand permissions, environment variables and history: the basics you will use in every other path.