Unix/Linux/BSD Security

Antivirus
While Linux is less commonly targeted by viruses, it is not immune. The Office of Information Technology recommends installing Microsoft Defender on SIU-owned devices to scan for malware, especially if you're sharing files with Windows or Mac systems. To setup Microsoft Defender, submit a ticket or email security@siu.edu. 

Updates
Regularly update your system using your distribution’s package manager (e.g., apt, dnf, or pacman). These updates include critical security patches that help protect your device from newly discovered vulnerabilities. Enabling unattended upgrades (if available) can simplify this process.

Linux offers powerful tools to enhance your system's security:

User Privileges
Avoid logging in as the root user. Use sudo for administrative tasks to reduce the risk of unintentional system changes or malicious activity.

Firewall Configuration
Enable and configure a firewall using tools such as UFW (Uncomplicated Firewall) or firewalld to control incoming and outgoing network traffic.

File Permissions
Review and restrict file and folder permissions to limit access only to necessary users. Use commands like chmod, chown, and ls -l to manage and audit permissions.

Strong Passwords
Create strong, unique passwords or passphrases for all accounts. Use a minimum of 16 characters with a mix of letters, numbers, and symbols. Avoid dictionary words and personal information.

Download Cautiously

• Install software only from your distribution’s official repositories or trusted sources.
• Be cautious when downloading third-party .deb, .rpm, or AppImage packages.
• Verify the integrity of downloads using checksums (e.g., sha256sum) or digital signatures when available.
• Watch for scripts or installers that attempt to change system settings or add new users without notice.

Secure Links

• Type URL’s directly or use bookmarks rather than clicking on links in emails or messages.
• Hover over links before clicking to preview the destination URL (usually displayed in the bottom corner of your browser).
• Only enter sensitive information on websites with a padlock icon in the address bar—this indicates a secure connection.

Secure Browsers
Use secure, privacy-conscious browsers like Mozilla Firefox. Keep your browser updated and review your privacy and security settings regularly.