Perform a Security Scan with Lynis

1. Install Lynis (a powerful Linux security auditing tool):

   sudo apt install lynis -y  # For Debian/Ubuntu
   sudo yum install lynis -y  # For CentOS/RHEL

2. Run a system security audit:

   sudo lynis audit system
   

3. Review the security report:

   • Lynis provides a detailed security assessment, including:
     ✅ System hardening recommendations
     ✅ Unpatched vulnerabilities
     ✅ Weak SSH configurations
     ✅ File permission issues

   • The final report will include a hardening score and security improvement suggestions.

Additional Security Scanning Tools

✅ Chkrootkit – Scan for Rootkits

• Install:

  sudo apt install chkrootkit -y
  

• Run a scan:

  sudo chkrootkit
  

(Detects signs of rootkits and backdoors.)

✅ ClamAV – Scan for Malware

• Install:

  sudo apt install clamav -y
  

• Update virus definitions:

  sudo freshclam
  

• Scan the system:

  sudo clamscan -r /home
  

(Detects malicious files and threats.)

✅ RKHunter – Scan for Rootkits and Malicious Programs

• Install:

  sudo apt install rkhunter -y
  

• Update database:

  sudo rkhunter --update
  

• Run a scan:

  sudo rkhunter --check --sk
  

(Checks for suspicious files, hidden processes, and malware.)

✅ Nmap – Scan for Open Ports and Network Vulnerabilities

• Install:

  sudo apt install nmap -y
  

• Scan the server for open ports:

  sudo nmap -sS -sV server_ip
  

(Helps identify unnecessary open ports that may be security risks.)

Best Practices for Security Scanning

🔹 Schedule regular security scans using cron jobs.
🔹 Apply security patches immediately after vulnerabilities are detected.
🔹 Combine multiple tools for a comprehensive security assessment.
🔹 Monitor system logs (/var/log/auth.log) for suspicious activity.

By regularly scanning your Linux server, you can identify security weaknesses, fix vulnerabilities, and proactively protect your system against cyber threats.

While Linux is generally more secure than other operating systems, it is not immune to malware. Servers that interact with the internet, share files, or run untrusted software are at risk of infections, including:
✅ Viruses – Malicious code that can spread across files.
✅ Rootkits – Hidden tools used by attackers to maintain access.
✅ Trojans – Malicious programs disguised as legitimate software.
✅ Cryptojacking scripts – Malware that hijacks your CPU for cryptocurrency mining.

Regular malware scanning and proactive protection help prevent security breaches and data loss.