vaheeD khoshnouD

1. Run updates any time you can

sudo apt-get update && apt-get upgrade

2. Enable firewall protection

sudo apt-get install ufw
sudo ufw default deny incoming
sudo ufw default allow outgoing
ufw allow ssh
sudo ufw enable

3. Disable nonessential services that are prone to exploitation

sudo apt-get install systemd
systemctl list-units

Recognize which services could cause potential vulnerabilities to your system. For each service:

systemctl stop <service>
systemctl disable <service>
systemctl status <service>

4. Check for listening ports

netstat -tulpn

5. Scan for malware

sudo apt-get install clamav
sudo freshclam
sudo clamscan -r --bell -i /