For complete Linux computer/pc/laptop Internet protection and privacy, you need the following programs.
Linux Firewall program: All Linux systems come with a firewall program.  The Debian operating system comes with one called gufw (Graphical Uncomplicated Firewall”).  Which should be good enough , but these days there are better firewall programs you should look at This list comes from another google search.  They are reviewed from reviewers and many have different opinions on what are the best firewall programs from top to bottom. You should read a couple of the  reviews to get a better understanding of what each offer in protection.

Linux Antivirus program: No Linux system comes with a preinstalled antivirus program.  For Debian based operating systems you can install a free one called ClamAV that should do the job.   Then again, the hackers are bypassing it and you should look at these reviews of other antivirus programs. These programs are designed to protect you from viruses and malware.

Linux VPN program: Linux VPN programs are your best defense against malware.   VPN programs are secure and easy to use.  You can disable them when you want your IP address registered for a site you are visiting.  A VPN program scrambles your IP address (IP address is like a telephone number) so the site does not know where you are coming from and put you in 2 cities away.  This is good because its hard for malware to get installed on your computer remotely, just make sure you turn on the multi-hop feature. You are also protected on both ends with a secure connection.   If you are buying from a site your personal information will be secure and not seen.

Summing it all up: These programs are only good at protecting your financial, credit card, personal information as long as the site you are visiting is secure from hackers.  It is important to know that hackers are always trying to get into websites to steal your personal data.  As long a you use these programs you have did your part on protecting your personal information.  You are still at the mercy of the website protecting your data from hackers brute forcing to get into a backdoor of the website.  The website should do everything it can to locking down yourdata from hackers. Let me make it clear that malware is the worst.   Malware can lock your computer up so you can’t use it and be forced to reset the computer to factory settings, losing all word documents, spreadsheets, presentations that you have spent many hours working on and personal information.   Malware and viruses does this by opening a backdoor in your computer for hackers to steal your privacy. Often hackers will lock up all computers connected to the internet and demand a ransom to free them up.   And it will be too late for you to disconnect from the internet to try and free them up.  You see hackers install malware through the open door on your computer and malware doesn’t need the internet to do it’s damage to the computer/s once installed.