📦 Package Management (apt)

Ubuntu uses apt (Advanced Package Tool) to manage software. apt downloads software from trusted repositories and handles dependencies automatically. In competition, you'll remove unauthorized software and install security tools.

Core apt Commands

# Update the local package list (always run this first)
sudo apt update
 
# Upgrade all installed packages to latest version
sudo apt upgrade
 
# Install a package
sudo apt install package-name
 
# Remove a package (keeps config files)
sudo apt remove package-name
 
# Remove package AND its config files
sudo apt purge package-name
 
# Remove unnecessary dependencies
sudo apt autoremove
 
# Search for a package
apt search keyword
 
# List installed packages
dpkg --list
dpkg --list | grep nmap    # check if nmap is installed

Competition — Packages to Remove

• •nmap / zenmap — network scanners; competition prohibits them: sudo apt purge nmap zenmap
• •netcat (nc) — can be used as a backdoor: sudo apt purge netcat netcat-traditional netcat-openbsd
• •john / hashcat — password crackers: sudo apt purge john hashcat
• •wireshark — packet sniffer: sudo apt purge wireshark
• •nikto, aircrack-ng — vulnerability scanners: sudo apt purge nikto aircrack-ng

Competition — Packages to Install

• •sudo apt install ufw — firewall (if not already installed)
• •sudo apt install auditd — audit daemon for logging
• •sudo apt install libpam-pwquality — password complexity enforcement
• •sudo apt install fail2ban — blocks IPs after repeated failed logins