Bandit Level 4 Walkthrough

Level 3 ➔ Level 4: The Secret of Hidden Files

1. Analyzing the Mission Brief

According to the screenshot for Level 4, the objective is: "The password is stored in a hidden file in the inhere directory."

Key Insights from the Image:

• New Directory: We need to move into a folder called inhere.
• Hidden Files: In Linux, hidden files are files that start with a dot (e.g., .hidden_file). They do not show up when you type a normal ls command.

2. The Feynman Explanation: Invisible Floorboards

How does a file become "hidden"? It’s simpler than you think. There is no complex encryption involved; it’s just a naming convention.

The Secret Compartment Analogy:

Imagine you walk into a room and look around. You see a chair and a table. This is like a normal ls command—it shows you the obvious things.

However, under the rug, there is a secret floorboard. To see it, you have to specifically look for "everything," including the secret spots. In Linux, any file starting with a period (.) is treated as a secret floorboard. The system assumes these are boring configuration files you don't need to see every day, so it hides them by default to keep the room clean.

3. Step-by-Step Execution

Log in as bandit3. Now, we must first enter the directory and then reveal the hidden content.

# Step 1: Move into the 'inhere' directory
bandit3@bandit:~$ cd inhere

# Step 2: Try a normal 'ls' (It will appear empty!)
bandit3@bandit:~/inhere$ ls

# Step 3: Use the -a flag to show ALL files (including hidden)
bandit3@bandit:~/inhere$ ls -a
. .. .hidden

# Step 4: Read the hidden file (be careful with the dot!)
bandit3@bandit:~/inhere$ cat .hidden
2EW7BB2mSrrBCoWbdy6tS0Y99s9sK69d

What did we see in ls -a?

• .: This represents the current directory itself.
• ..: This represents the parent directory (the one above this one).
• .hidden: This is our target file!

🚀 Pro Tips: The Power User Way

✨ The "Long List" Combo

Instead of just ls -a, professionals usually use ls -la.
The -l adds "Long" format, which shows you file sizes and permissions. This is very helpful for spotting which hidden file actually contains data.

⭐ Reading from the Parent Directory

You don't always have to cd into a folder to read a file. If you are still in the home directory, you can reach inside the folder directly by using the path:

cat inhere/.hidden

4. Why does this matter?

In real-world Linux systems, sensitive information like API keys, SSH keys, and configuration settings are almost always stored in hidden files (like .bash_history or .ssh/). Learning to find them is step one in any security audit.

Level 4 Complete!

You've discovered the "invisible" world of Linux. Save your password and prepare for Level 4 ➔ Level 5, where we start hunting for files based on their type!

Tags: #Linux #Bandit #OverTheWire #HiddenFiles #LsCommand #CdCommand #CyberSecurity #FeynmanTechnique #CodeWithPritom #ProTips