There is an eternal controversy between Linux users: is there an antivirus needed in Linux?
In Windows, it is clear that without the antivirus, that PC is dead (even if its “owner” is not aware of it). The computer shuts itself down, strange windows with text that you do not understand, or tens/hundreds of windows that you can not shut down, emails are sent automatically – the reason for all these can be only one: the system has a virus. The main reason is that Windows is running.
Linux has very few viruses. A Linux virus is very hard to encounter; and if a system has been infected, the damages made by that virus are minor due to the very well-tuned permission system.
Linux uses an extremely efficient permission system. In Windows, the user (and every installed program) has the right to do almost everything he wants in the system. Anyone who wants to hurt you and have access to your Windows system for a few seconds (or even you, unique users of that system, you can accidentally delete an important file), browse to the system folder and delete vital files: Windows will not complain, but your work, the owner, is lost.
But imagine if you can delete these files, other programs also can. Linux does not allow this. Every time you ask for something related to the system, an administrator password is required (and if you are not an administrator, you can not modify the system). Viruses can not walk and erase everything they want from the system: they do not have the necessary authorization.
In Linux, most programs (99.99%) are installed from the software repositories. Well, in these warehouses get only checked and scanned packages, so it’s impossible to infect your system if you only install programs from official warehouses.
Another reason why Linux has very few viruses is that Linux is an open source. Several eyes that look at source code quickly discover vulnerabilities. Being open source means that any programmer in the world can look at the source code (the ingredient of each program) and can help or just draw attention to the discovered vulnerability.
A so-called reason outlined by Windows lovers and users is that Linux has no viruses because it is installed on far fewer systems than Windows. Wrong! Almost all servers in the world run Apache on Linux which, unlike the Microsoft IIS competitor, has far fewer vulnerabilities; Linux is found where you do not expect (routers, phones, Smart TVs, planes, etc.), and what is discovered is covered very quickly, precisely because of the freedom it enjoys.
However, Linux can also be infected. The last Linux virus I’ve heard of is Ebury, a rootkit that affected the SSH. And that’s it! It’s the only Linux virus I’ve heard about!
Returning to the question in the first paragraph: Does Linux need antivirus?
There are two answers:
1. NO, if you do not have a dual-boot system and do not interact too much with other Windows users (you are not an intermediary in file shuffles between 2 or more Windows users).
2. YES, if you have Windows in dual-boot with Windows and also to protect the Windows systems you are in contact with (you have downloaded an executable file from user_windows_1, scan it on Linux and pass it on to user_windows_2 ). In other words, use antivirus in Linux to scan files from Windows, because poor Windows can not defend itself, being dead without the help of Linux. YES, if you run web servers or mail servers to scan files from Windows – to prevent infected Windows machines from uploading viruses on the Linux server and from here to get to other Windows machines to virus them.