How to Perform Regular Server Security Audits

How to Perform Regular Server Security Audits

Regular security audits are essential to maintaining the integrity, performance, and safety of your dedicated server. By conducting routine audits, you can identify vulnerabilities, prevent unauthorized access, and enhance overall server security. Follow this step-by-step guide to perform a security audit on your QuickServers dedicated server.

Step 1: Update Your Server and Software

• Ensure that your operating system and installed software are up to date.

• Run the following command to update your package list and upgrade all installed packages:

  sudo apt update && sudo apt upgrade -y
  

• For CentOS/RHEL users, use:

  sudo yum update -y
  

• Keeping software up to date helps patch security vulnerabilities.

Step 2: Check User Accounts and Permissions

• List all users on the server:

  cat /etc/passwd
  

• Remove any unauthorized or unused accounts:

  sudo userdel -r username
  

• Verify user privileges:

  sudo cat /etc/sudoers
  

• Ensure only trusted users have administrative privileges.

Step 3: Scan for Malware and Rootkits

• Install and run ClamAV for malware scanning:

  sudo apt install clamav -y
  sudo freshclam
  sudo clamscan -r /home
  

• Check for rootkits using rkhunter:

  sudo apt install rkhunter -y
  sudo rkhunter --update
  sudo rkhunter --checkall
  

• Review the scan results and take action if necessary.

Step 4: Analyze System Logs for Suspicious Activity

• Review authentication logs:

  sudo cat /var/log/auth.log | grep "Failed password"
  

• Check system logs for anomalies:

  sudo cat /var/log/syslog
  

• Identify any unusual login attempts, failed access attempts, or unauthorized changes.

Step 5: Audit Open Ports and Active Services

• Check active network connections:

  sudo netstat -tulnp
  

• List open ports:

  sudo lsof -i -P -n | grep LISTEN
  

• Disable unused services to reduce potential attack vectors:

  sudo systemctl disable service-name
  sudo systemctl stop service-name
  

Step 6: Verify Firewall and Security Settings

• Check firewall rules:

  sudo ufw status
  

• Allow only necessary ports and block all others:

  sudo ufw allow OpenSSH
  sudo ufw allow 80/tcp
  sudo ufw allow 443/tcp
  sudo ufw enable
  

• Ensure the firewall is active and properly configured.

Step 7: Enable Intrusion Detection and Prevention

• Install and configure Fail2Ban to block repeated unauthorized login attempts:

  sudo apt install fail2ban -y
  sudo systemctl enable fail2ban
  sudo systemctl start fail2ban
  

• Review Fail2Ban logs to check for blocked IPs:

  sudo cat /var/log/fail2ban.log
  

Step 8: Automate Security Audits

• Set up a cron job to run security scans automatically:

  sudo crontab -e
  

• Add a scheduled security check, such as a weekly ClamAV scan:

  0 2 * * 1 clamscan -r /home
  

• Automating audits ensures continuous security monitoring.

Step 9: Secure Remote Access

• Disable root login via SSH:

  sudo nano /etc/ssh/sshd_config
  

• Locate and modify the following line:

  PermitRootLogin no
  

• Restart SSH to apply changes:

  sudo systemctl restart ssh
  

• Use key-based authentication instead of passwords for added security.

By following these steps, you can regularly audit your QuickServers dedicated server, identify vulnerabilities, and strengthen security against potential threats. Conducting frequent audits helps maintain the reliability and performance of your server while safeguarding critical data.