Although Linux Operating System considered being safer compared to the other operating systems currently in use, in some cases it would be better to use antivirus programs. Here are the 5 best free antivirus programs for Linux users.
1. ClamAV

ClamAV which is a free and open-source antivirus toolkit for Linux systems is highly preferred by the Linux community. While detecting trojans, malware, and viruses, ClamAV supports all mail file formats. It’s also available for Windows and Mac OS, but the on-access scanning feature is only available in Linux. This antivirus software that you can install and easily use also scans archives and compressed files. Database updates are frequent, and this is the best and probably widest embraced antivirus in the Linux community. It is recognized as a versatile antivirus to detect trojans, malware, and viruses. It also supports standard mail gateway scanning which is a feature used widely on UTM systems. It is easy to use and fast to run because it doesn’t have a native GUI and works through the terminal.
2. Comodo Antivirus for Linux

Comodo antivirus program for Linux provides proactive virus protection and email filtering. With its additional features for the fully configurable anti-spam system, it has the advantage of email filtering including Postfix, Qmail, Sendmail and Exim MTA’s. After a quick installation, it is easy to follow instructions to start the scan scheduler and event viewer. It is optional to set up automatic updates, it has alarms just for solid virus incidents. In addition to its cross-platform feature, this one of the best antivirus for Linux supports Windows Firewall feature with 32-bit and 64-bit architectures.
3. Sophos for Linux

One of the best and most reliable antivirus software around, Sophos has real-time scanning feature, but it is not possible only on-demanding scanning. It works fine and quietly on Linux and as it is on Windows and Android. It has detection and eradication for malware and viruses including worms and Trojans. Sophos also provides detection and blocking for all non-Linux threats from the Linux system. Sophos works through the command line, is lightweight and free to use.
4. ChkrootKit

To deal with rootkit problems you should be utilizing some ways to detect them first. One of the most known rootkit scanners out there is ChkrootKit. ChkrootKit is a portable solution which means you can burn it on a CD or DVD, or more conveniently write it on a USB stick to have it around with you. That is the proper way to use a rootkit checker since rootkits are generally present at the start and can obfuscate themselves from regular AV products. Of course, you do not have to use ChkrootKit with an external drive; it can be installed to a system and can be used easily from the command line.
5. Rootkit Hunter

Another good rootkit detector is Rootkit Hunter which, along with rootkits as the name suggests, detects viruses and Trojans that are using backdoors and other local exploits. This scans process work through SHA-1 hash comparison. It can be used for Linux and FreeBSD through the command line. Rootkit Hunter is also portable which provides another ease-of-use point for rescue operations.
6. F-PROT for Linux

F-PROT anti-virus for Linux is also another free, yet powerful anti-malware engine. You can use the scanner for your home/personal workstations. F-PROT anti-virus offers full protection against any type of malware like macro viruses and trojans. The scanner supports both 32bit and 64bit versions of Linux. You can install it on any Linux distro that you are using. You can set schedule scans using cron. It scans all hard drives, USB disks, CD-ROMS, network drivers, directories and specific files. F-PROT also can scan the images for boot sector viruses, macro viruses, and trojans.
7. ClamTK

ClamTK is the updated version of ClamAV. The lightweight GUI lets the users have an easy-to-use anti-malware software experience. Because ClamTK provides a GUI, any Linux end-user can also start malware scanning by just simple clicks. It is an on-demand virus scanner, so there is no real-time protection, which means you have to be careful while surfing on the internet and scan the suspicious files before performing any action.