Many people say using an antivirus program with Ubuntu is not necessary. It’s hard to argue. There are practically no viruses or malware for Linux at the present time. There’s some debate about whether this will change in future, but right now an Ubuntu user is quite simply safe from viruses. No further action is required.
However, aside from guarding against future threats, installing an antivirus program allows you to watch out for Windows or even Mac viruses in files sent to you. Therefore, you can avoid passing on virus-infected files that might affect those running non-Linux operating systems.
TIP Why not convert your friends or colleagues to using Ubuntu? The fact Ubuntu is immune to viruses is a very persuasive argument in its favor. If you do convert them, be sure to suggest they get a copy of Ubuntu Pocket Guide and Reference to help them get started!
There is a variety of commercially sold antivirus programs for Linux, but perhaps the best choice from an open source perspective is ClamAV. This is industrial-strength antivirus designed for server computers, but you can also install ClamTK, a small program that provides a graphical front end, and thereby makes ClamAV suitable for more humble users.
Installing ClamTK
Start Synaptic and search for clamtk. Put a check alongside the clamtk entry in the results, and click Mark for Installation in the menu that appears. Agree to install the list of dependencies, that includes ClamAV itself, and then click the APPLY button on the toolbar.
When ClamTK is run for the first time it’s necessary to update the virus database. In future this will be done automatically and periodically in the background, without any need for user intervention.
To manually update the database, ClamTK needs to run as root user, so open a terminal window (Applications | Accessories | Terminal), and type the following:
$gksu clamtk
Click Help | Update Signatures. Once ClamTK reports the signatures are up to date, close the program window.
TIP You can update the virus database at the command-line by typing sudo freshclam. Don’t worry if, while doing this, you see a warning that ClamAV is out-of-date—this simply means that the version offered in the Ubuntu repositories is lagging a little behind the main releases. This is not an issue.
Scanning for viruses
To start ClamTK, click Applications | System Tools | Virus Scanner.
It’s not a good idea to scan the entire filesystem using ClamTK, because ClamAV simply isn’t built for that task. In fact, in my tests, any attempt to do a full filesystem scan caused ClamAV/TK to crash.
Therefore, you should limit scans to your /home folder. This is where virus-infected files are most likely to be found because it’s where most files you download will end-up.
Before starting a scan, ensure that ClamAV scans hidden files by clicking Options | Scan Hidden Files (.*).
To start a scan of your /home folder, click File | Home (Thorough). If using Ubuntu 8.04, click File | Full Home Scan.
Any virus-infected files found will be listed under the File heading in the ClamTK program window, along with their location (path). The type of virus infection will be listed under the Status heading. You may see other files listed in the results area after a scan. If a file was too big to scan, it will be listed. If you wish to have ClamAV scan all files, regardless of size, click Options | No Maximum Size. Bear in mind this may dramatically increase the time taken to scan.
ClamAV is unable to remove any virus infections found in a file. Instead, the user must decide the course of action to take. Usually, deleting the file is best.
All antivirus programs are prone to false positives—identifying files as containing viruses when they don’t. To guard against this, should ClamAV report what it thinks is an infected file, search Google, specifying the name of the file and the name of the virus. If one or more people have encountered a similar result, that can help identify a false alarm.
Sumber : ubuntu pocket guide
