- Security
Protecting yourself from cyber threats: the habits that count
Reading a sender's address, choosing passwords, backing up your files: the digital hygiene guide for beginners, and what the padlock does not guarantee.
202612 min - Security
Learning offensive security: where to start
A complete path into offensive security: the French legal framework, four technical foundations with mastery criteria, lawful practice environments and job roles.
202615 min - Security
Introduction to hashing
Understanding hashing: the properties of a cryptographic function, how it differs from encryption and encoding, the sha256sum and Get-FileHash commands, the state of MD5, SHA-1, SHA-256, and password hashing.
202615 min - Security
Learning cybersecurity - Hands-on activity: secure deployment of the Bitw password manager
Deploying Vaultwarden in a Docker container, then publishing it over HTTPS with a self-signed certificate and an nginx reverse proxy configuration file.
20241 min - Security
Learning cybersecurity - Hands-on activities on data encryption
Four hands-on encryption activities: file encryption with GPG, an encrypted VeraCrypt container, OpenSSL on Linux, and client-side encryption with Crypto-JS.
20243 min - Security
Learning cybersecurity - Hands-on activities in secure development
Hands-on secure development exercises: validate user input, block SQL injection with prepared statements, and prevent XSS flaws in PHP applications.
202413 min - Security
Learning cybersecurity - 7 hands-on network security activities - Part I
Seven hands-on exercises: nslookup, WHOIS, netstat, traffic analysis with Wireshark, a firewall rule, a self-signed HTTPS certificate, then Certbot.
202411 min - Security
Learning cybersecurity - Introduction to computer security
An introduction to computer security: what it protects, the technologies involved, the roles behind it, real cyberattacks and how to defend yourself.
20247 min - Security
Initial security configuration of a Debian- or Ubuntu-type Linux server
The basic setup steps for a new Debian or Ubuntu server: connecting over SSH, creating a user, granting sudo privileges, the UFW firewall and external access.
20238 min - Security
Hardening your web server: a security guide for Nginx and Apache
Several security options to consider when configuring a VirtualHost on Apache or a Server Block on Nginx: HTTPS, HTTP/2, security headers and DoS protection.
202311 min - Security
How the Brave browser changes your life - Ad blocker, security and privacy
An overview of the Brave browser: built on Chromium, it blocks ads and trackers, adds security features, and rewards users who opt in to see ads.
20234 min - Security
Hacking a MYSQL database with Metasploit - Bruteforce attack on Metasploitable
Using Kali Linux and Metasploit against a Metasploitable2 target, scan a MySQL database on port 3306 and run a bruteforce login attack to gain access.
20234 min - Security
Hacking a Samba server with Metasploit - Exploit on Metasploitable
A step-by-step walkthrough of the Metasploit usermap_script exploit against the Samba server of a Metasploitable2 machine, from the nmap scan to the shell.
20234 min - Security
How do I check whether I have already been hacked, using Have I Been Pwned?
Using Have I Been Pwned to find out whether an email address or a password appears in a public breach database, and what to do when it does appear.
20222 min - Security
Hardening the security of the OpenSSH service with SSH encryption keys
Password authentication is a weak mechanism. This guide sets up SSH key authentication on the OpenSSH service and then disables password login entirely.
20223 min - Security
How to carry out a Man-in-the-Middle - MITM attack on the SSH protocol
A hands-on Man-in-the-Middle attack on SSH: install SSH-MITM on Kali Linux, run the attack with ettercap, capture the transmitted data, and harden OpenSSH.
20223 min - Security
How to encrypt and decrypt messages with the Kleopatra software
Install Kleopatra, create an OpenPGP key pair, export and import a public key, then encrypt and decrypt a message step by step, with screenshots.
20229 min - Security
How to set up a secure email exchange with a PGP protocol?
Setting up encrypted email with PGP, two ways: Mailvelope for Gmail and Thunderbird with OpenPGP, from installing the software to creating and sharing keys.
20229 min - Security
How to encrypt data with VeraCrypt on Linux
Install VeraCrypt on a Linux distribution, create a standard encrypted file container with AES and SHA-512, then mount it to store your files securely.
20227 min - Security
How to crack password hashes with Hashcat on Kali Linux
Crack password hashes on Kali Linux with Hashcat: a refresher on hashing, why use Hashcat, how to install it, a dictionary attack, and cracking /etc/shadow.
20228 min - Security
What is cryptology?
Cryptology, the "science of secrecy", covers cryptography and cryptanalysis. A look at its history, symmetric and asymmetric encryption and the CIA model.
20227 min - Security
Comparison between WireGuard and other protocols
WireGuard set against commercial VPN providers, OpenVPN and IPSec/IKEv2: code size, speed, cryptographic libraries and what self-hosting brings you.
20213 min - Security
5 things you need to know about VPNs
A virtual private network is a secure tunnel between computers over the Internet. Five things to know about VPNs: privacy, encryption, geoblocking, free vs paid.
20215 min - Security
Everything you need to know about WireGuard
What WireGuard is, how this VPN protocol works, its advantages and its limits, and which commercial VPN providers already support it on their networks.
20215 min - Security
Create your own VPN with WireGuard on Docker
Set up your own private VPN server with WireGuard running in a Docker container: installation, the docker-compose file, and adding clients to the server.
20213 min - Security
Learn how to configure your WireGuard
Install the WireGuard client on Windows, import a .conf tunnel file, activate the tunnel, and then check that your connection really goes through the VPN.
20212 min - Security
Securing SFTP access with Chroot and blocking the use of SSH
Set up an SFTP Chroot Jail so that some users can only transfer files, confined to their own directory, and cannot open an SSH shell on the system.
20215 min - Security
A few basic notions of computer security
The main types of computer security, the most common forms of malicious software, and the skills to work on first in order to move into cybersecurity.
20216 min - Security
Designing a Trojan horse virus with Kali Linux
Hands-on exercise: build a Meterpreter payload with msfvenom on Kali Linux, encode it, then open a reverse shell session to understand how attackers work.
20217 min - Security
Kali Linux
A beginner's walkthrough of Kali Linux: what the distribution is, who uses it, and a hands-on boot-to-root against the Mr. Robot vulnerable virtual machine.
202110 min - Security
Recommended security measures to protect your servers
Four practical measures to protect a server: audit the running services, enable unattended updates, disable directory indexes and back up frequently.
20217 min - Security
Information system security concepts
An introduction to threats, risks and vulnerabilities: security perimeter, access rights, authentication and encryption, firewalls, DMZ and intrusion detection.
20218 min - Security
Network attacks
An overview of the attacks that can affect a network and its systems: the layers they target, a typology of security weaknesses, and network mapping attacks.
20216 min - Security
Secure Remote Access with SSH
What SSH is and how it works, how to install the OpenSSH server and client, how to connect from PuTTY or a terminal, and how to harden the sshd_config file.
202111 min - Security
Securing your server
Twenty-one server security practices: SSH and key authentication, FTPS, SSL, VPN, user and password management, updates, firewall, backups and isolated environments.
202113 min - Security
Types of virtual private network (VPN) and their protocols
The two families of virtual private network, remote access and site to site, and the protocols behind them: IPSec, L2TP, PPTP, SSL/TLS, OpenVPN, SSH, WireGuard.
20205 min