Viruses and Linux and Linux Antiviruses

Viruses and Linux

Computer viruses are pieces of software that replicate themselves on a computer. The replication means a virus is distributing itself all over your computer, making it tough to get rid of. Viruses seem to understand that there’s safety in numbers. Viruses can destroy data or send it out to a malicious third party, meaning someone creepy could be viewing your passwords, your financial documents, and even your photos. Computers become infected in any number of ways, but the commonality is that the user is tricked into installing it, either by visiting a dangerous site, installing a piece of software, or downloading an email attachment.

Is Linux immune to viruses?

Antivirus is an important part of Windows security but because Linux is constructed differently from Windows, it’s less important. But don’t interpret that as “Linux is immune to viruses.” It’s not. (Software from repositories could, in theory, become infected with a virus, but it’s highly unlikely.) But in general, Linux tends to be safer from viruses than Windows. Why? Part of it is the nature of Linux, which as we just learned, assigns permissions to users. If you’re a Linux user with administrative rights, you probably know enough to avoid viruses. Contrast that with other operating systems, where it might be easy to trick anyone using the computer into installing a virus. Another part of what makes desktop Linux safer than Windows is that the market share is relatively small, not a lot of creepy people are designing viruses for it. This is not to say that getting a virus on Linux is impossible. It’s not. But there’s enough security between you, the knowledgeable user, and your system, which has its own protections, for you to feel reasonably safe.
Linux antiviruses

But what if reasonably safe isn’t enough? What if you want to be exceptionally safe, like wearing suspenders and a belt? I respect your caution! Linux actually has some antivirus tools. The most popular program is called ClamAV. It’s cost-free for Linux (and for Windows; the OS X version is a paid product). ClamAV detects viruses on your system that you can then remove. It’s a terminalbased program but there is a graphical front-end called ClamTk you can install. It lets you use ClamAV as a graphical program, which is why it has a slightly different name. Some users might find the graphical program easier for configuring preferences. Let’s install the graphical version and work with that.

ClamTk

1. Install ClamTk with sudo apt-get install clamtk.

2 Update its virus definitions with the command sudo freshclam.

You might get a message about your version of ClamAV being outdated. That’s because Ubuntu doesn’t always have the most recent version in the repositories. It’s not ideal but don’t worry about it for now.

If you want the most recent version, you can install it from the CalmAV site: www.clamav.net/. The virus definitions, which are used to find and identify viruses, will be up-to-date either way.

Once it finishes the update (it might take a while, so this might be a good time to eat some of your lunch), launch it via the Dash. The antivirus definitions should read as Current.

To run the antivirus, click the Home button, which will scan your home directory. You can configure a more specific scan by using the Scan menu (shown in the figure at right).

3 When it’s done, you’ll get a report of files scanned and threats found.

Any viruses can be quarantined by ClamTk and manually removed by you. Just be careful that you’re not deleting something important.

If the file is something forwarded to you by that friend who forwards you everything, it’s probably safe to assume it actually is a virus.