Sunday, July 5, 2009

Installing Antivirus Software

One common misconception about GNU/Linux is that no viruses exist for this operating system. This is simply not true. For quite some time GNU/Linux did not feel the constant pressure of malware attacks that Microsoft Windows did. While researchers did write viruses that could infect the GNU/Linux operating systems, they were for research purposes only. However, viruses have since been released that have the ability to infect computers running a GNU/Linux operating system. More and more, people are beginning to see viruses “in the wild” that can damage these operating systems.

A virus that has been released to the public is said to be “in the wild.” This is how security experts can differentiate between a virus that is for research and one whose intent is to cause harm to a computer system. Purely as a hobby some people collect malware “in the wild” so that they can analyze the code of the malware and help fight against it.

Ubuntu, remember, was built on the philosophy that Ubuntu “Just Works.” For Ubuntu to work properly, antivirus software had to be made available to the users of Ubuntu. Antivirus software works in a number of ways. First of all, this software needs to have the ability to detect malware on a computer system by knowing what to look for. This information is provided by a signatures file that the software will download and install automatically. If these signatures are outdated, then the computer is vulnerable to the latest malware.

Signature files are also called “definition files” by certain antivirus applications.

Since most antivirus software manufacturers charge not only for the application but also for a yearly subscription for the virus definitions file, finding one that fits the Ubuntu software model might seem a bit difficult. Fortunately, quite a few companies have opted not to charge home users for antivirus software and the definitions. From this list, the Ubuntu community chose ClamTk since it falls under the GNU Public License.

Installing ClamTk
Installing ClamTk is very easy. Start by going to the Add/Remove tool. You do remember how to get there, right? From the categories on your left, select System Tools and then scroll down the list until you see Virus Scanner. From here simply select this application and then click Apply Changes as you have done before. VoilĂ ! You have protected your computer against malware.

Updating the Signature File
Now that you have successfully installed the application, you will want to update the signature files. The easiest way to do this is to open the terminal window and type the following:


When you press ENTER, it displays the download process of the virus signature file. Now, you need to move the file to the proper directory by typing

sudo mv daily.cvd /var/lib/clamav

This will put the updated file into the clamav folder so that the application will use the latest signatures. Once you press ENTER, you will be asked for your password. Upon entering this successfully, you will be taken back to the terminal prompt. You can now exit the terminal so you can run a virus scan.

Scanning the Computer
While most antivirus applications that run on Microsoft Windows actively scan the computer for malware, ClamTk does not. Instead, you are required to do a passive scan where you actually tell it to scan the computer for malware. Remember, while some malware can infect a computer running GNU/Linux, few can. The odds of you picking up a virus in the wild are slim, and if you only install software from the repositories, then you have a good chance of never having an infection. However, it is still a good idea to scan your computer from time to time. Once a week is a good schedule for most users, while those who download a large number of files and who open e-mail attachments may want to scan their computer more often. To scan the computer, you need to launch the ClamTk window from the Applications tab. However, if you open this tab, the System Tools category where ClamTk resides may not be listed there. If you find this to be the case, instead of opening the Applications tab, right-click it and select Edit Menus so that it brings up a window. Now select System Tools and then place a check mark next to Virus Scanner. Click Close and open the Applications tab. Select System Tools | Virus Scanner to launch the application.

Now that the application window for ClamTk is open, select File and then Full Home Scan. This will scan your home directory. You can also select to scan individual files if you downloaded something questionable, or individual directories for security reasons.

Source of Information : McGraw Hill Osborne Media How to Do Everything Ubuntu

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