How to Install and Use ClamAV Antivirus on Ubuntu Linux

ClamAV is one of the best-recommended antiviruses for Ubuntu^[1]. Of course, you will be
cynical if I say instead of being a modern Ubuntu user, sometimes
you might need an antivirus as we all know that Linux is always
unsinkable in the sea of the virus. But, this notion is not valid
in some cases. If your system is connected with the internet, there
are thousands of ways you can carry the virus in your Ubuntu
system. For security purposes, Ubuntu often needed to be checked
up; It’s good to maintain a healthy operating system without having
any virus attack. And no doubt, ClamAV^[2]
Antivirus is the finest and most used antivirus for the Ubuntu
system.

ClamAV Antivirus on
Ubuntu

If you have to
deal with public domains or third party databases, there is a
chance that your Linux system can get infected with the virus.
Mostly, Linux viruses are trojan and malicious^[3]
files. Ubuntu, the leading Linux operating system in the world,
runs a vast amount of file servers, where there is a huge chance to
get malicious emails or malicious SQL injection^[4]
form evil users.

To protect your Ubuntu system or database from hackers, it’s a
wise decision to have an antivirus. And for Ubuntu, no other
antiviruses can be as effective and powerful as ClamAV. ClamAV can
scan, find, and remove all infected files and software from your
Ubuntu machine. ClamAV can also defend the local attacks delivered
by ethical or unethical hackers. In this blog post, we will see how
to install and use the ClamAV Antivirus in any Ubuntu machine.

Install of ClamAV Antivirus in
Ubuntu Linux

ClamAV claims that it can be installed in all Debian
distributions of the Linux like Ubuntu, Linux Mint, Elementary OS,
Debian OS, etc. Here I’m going to start the method of installing
ClamAV Antivirus in Ubuntu. Be mindful that before installing any software in Ubuntu^[5], you should keep your
Ubuntu repository up to date.

Step 1: Get Your Ubuntu System
Updated

So first thing first. Let’s update our Ubuntu machine; later,
when the file repository will be updated, we will initialize the
process of installing ClamAV. For now, I will be using the Advanced
Package Tool apt command in the terminal to get
updated.

$ sudo apt-get update
$ sudo -E apt-get update
$ sudo apt update

Step 2: Installing ClamAV in
Ubuntu

Installing ClamAV Antivirus in your Ubuntu is very simple. All
you need is to run an apt install command in your
system terminal. For installing ClamAV in the background process,
I’m adding a daemon with the terminal command. You can
also check the version of your ClamAV by using the following
command in the terminal.

$ sudo apt-get install clamav clamav-daemon
$ clamscan --version

So far, you’ve successfully installed ClamAV Antivirus in your
Ubuntu system. But like Windows antiviruses, the Ubuntu antiviruses
don’t always run in the system background. ClamAV only runs when
the system administrator asks it for any particular job. Otherwise,
it keeps sleeping.

If you are a Linux
system administrator, and if you think that something wrong is
happening inside your Linux server or filesystem, you can also
install ClamAV on your website
C-panel.^[6]

Step 3: Update the ClamAV
Signature Database Automatically

In Ubuntu, the ClamAV signature database is the special database
for your ClamAV antivirus, where all the local software, log files,
and system files kept safely. Only you can get access to your
ClamAV signature database from your Ubuntu system. ClamAV Antivirus
signature database keeps unwanted users away from your Ubuntu
system.

When any update comes for ClamAV, the corresponding files are
also updated inside the ClamAV signature database. Moreover, the
ClamAV signature database also allows users to use ClamAV in
offline. To install the ClamAV signature database in your Ubuntu,
you need to stop your running ClamAV in your machine. To stop the
freshclam, simply follow the terminal command.

$ sudo systemctl stop clamav-freshclam

Now when the background process of ClamAV Antivirus is
stopped, you can run the following terminal command in your Ubuntu
machine to update the ClamAV database automatically. You can also
update your ClamAV signature database manually; we will also see
that process after a while.

$ sudo freshclam

Step 4: Update the ClamAV
Signature Database Manually

If you think you won’t be able to run the above terminal command
to get an automatic update of your ClamAV database, there is a
second method to update your signature database. You can download
the ClamAV signature database from the official directory of
ClamAV.

Download ClamAV
Database^[7]

After you have downloaded the ClamAV signature database, now all
you need is to place the file in your local directory of ClamAV.
You can use the following mkdir terminal command to
create a directory for ClamAV, or you can also find your
var/lib directory and create a new folder then rename
it with ClamAV.

$ sudo mkdir /var/lib/clamav

Now you’ve to move the ClamAV signature database inside the
directory. Again, you can either use the following terminal command
to move the file, or you can do that in the traditional manual
way.

$ cp daily.cvd /var/lib/clamav/daily.cvd

Step 5: Starting ClamAV Antivirus
in Ubuntu

Finally, so far, you’ve done the procedure of installing the
ClamAV antivirus inside your Ubuntu machine. Now it’s high time to
open the ClamAV. To open the ClamAV antivirus, just type the
following terminal command in your Ubuntu machine. Later, we will
see how to use ClamAV and how to remove harmful and malicious files
from our system.

$ sudo systemctl start clamav-freshclam

ClamTK, the GUI Control Panel of
ClamAV

Those who have recently moved on Ubuntu from Windows^[8] might not be familiar
with the method of using terminal commands. For them, ClamAV has
built a graphical user interface(GUI) control panel. The GUI panel
of ClamAV is known as ClamTK. Now we will see how to install ClamTK
in our Ubuntu machine. To install ClamTK on Ubuntu, just follow the
terminal command in your machine.

$ sudo apt-get install clamtk

Main Features of ClamTk on
Ubuntu

The main features of ClamTK are shortlisted here. This might be
helpful to you, have a glance.

• Scan files that are larger than 20MB
• Make a whitelist of directory or software
• Schedule the antivirus for checking up
• Scan your network addresses
• Scan emails and web browsers
• Scan a specific file or directory
• Analysis system health
• Check the previous history
• Quarantine any apps or files for a certain period

How to Use ClamAV on
Ubuntu

After the installation process of ClamAV and ClamTK are done
inside your Ubuntu machine, now you are good to go for a test run.
Very first, you can check the to-do list of ClamAV. You can find
what you can do with ClamAV. To get the to-do list of ClamAV, open
your terminal and type the following command line in the terminal.
A new list will be generated in your terminal, showing the
capabilities of ClamAV Antivirus.

$ clamscan --help

You can scan and get auto-remove trojan and malicious files from
your Ubuntu system with ClamAV. For that, type the command kept
below in your terminal. But my recommendation will be not to use
the autoremove command, because if you’re using a dual boot
machine, sometimes ClamAV recognizes and removes all other
operating directories as a virus. This can become a huge loss of
data from your machine.

$ sudo apt-get autoremove
$ sudo clamscan --infected --remove --recursive

You can also scan any specific directory or file in your Ubuntu
by ClamAV. For that, you can use the remove infected
-r-i- command in the terminal. Every time the ClamAV
finds an infected file, it will ring a bell. For example, let me
want to scan my Downloads directory, for that my
command will be like the command given below.

$ clamscan -r-i --bell ~/Downloads

Removing ClamAV from
Ubuntu

It is true that, like other Linux distributions, Ubuntu also
doesn’t require any third-party anti-virus protection. But in case
if you need to check the health of your system, you have ClamAV.
But what to do when you don’t need ClamAV anymore! Yes, you can
remove/uninstall the ClamAV Antivirus from your Ubuntu system.

Basically, Ubuntu users install ClamAV occasionally just to
checkup the system condition and remove it after they are done
checking. So, if you need to remove ClamAV from your Ubuntu, here
is the terminal command to do so.

$ sudo apt-get remove clamav clamav-daemon

Final Thoughts

Ubuntu Linux, the leading open-source operating system, doesn’t
require any third-party antivirus as Windows requires. But in case
any malicious or trojan files get mixed with your system files, it
is necessary to check your Ubuntu system with ClamAV. Using ClamAV
is a relief and hassle-free, because, like Windows, it doesn’t keep
running in the background or doesn’t show any annoying pop-up
window.

In the entire post, I’ve tried to describe all the process of
how to install and use ClamAV Antivirus in your Ubuntu machine.
I’ve also covered pretty much about why you might need an antivirus
in your Linux machine. And at the last part, I’ve also detailed the
process of how to uninstall ClamAV Antivirus from your Ubuntu
machine.

So, what do you think? Does Ubuntu require any third party
antivirus? If the answer is yes, tell us about your experience.
Fell free to share your thoughts with us. You can also share this
post with your Linux geeky friends.