Computer Help Blog

Many people who are new to Linux often wonder if it is necessary to install antivirus software on their computer. Some people even try to install antivirus software meant for Microsoft Windows on Linux! If you’re new to Linux, you might be wondering if it is actually necessary to install an antivirus software scanner on your Linux machine. The answer is — no!

The reason is: Most viruses are written for Microsoft Windows. There are people who claim that it is difficult to write viruses for Linux. This is because Linux is inherently more secure when compared to Windows. This may or may not be true — there are people on the opposite side who claim that both Windows and Linux are equally insecure. Another reason why there are very few viruses specifically aimed at Linux may be that not many people use Linux as a desktop system. The common computer-user is not very unlikely to use Linux. This is exactly the market segment that virus-writers target.

Irrespective of the reason and the outcome of the debates, we can say for certain that there are very few viruses for Linux. There are certain worms written specifically to attack Linux-based systems, but, these are mainly aimed at Web servers and not desktop computers.

It is safe to conclude that by running Linux, you are much likely not to encounter viruses and other malware. Most of the viruses which spread through e-mails and infected websites cannot cause any harm to the computer. For this reason, it is not necessary to install antivirus software application on your computer if you’re running Linux.

Certain antivirus companies such as AVG have versions for Linux as well. However, as it was mentioned before, these are not meant for desktop systems — these are meant for servers. You can download and install these for added security, but it is not necessary at all. This is one of the major reasons why many people switch to Linux.

Virus programs avoid detection by the user and antivirus programs using a variety of techniques. As technology progresses, newer techniques have to be used to make the virus more effective…

In order to avoid detection by users, viruses programs use different kinds of deception techniques. Older viruses, especially viruses designed for MS-DOS made sure that the “last modified” date of a host file stayed the same when the file was infected by the virus. This approach does not fool anti-virus software, however, especially those which maintain and date Cyclic redundancy checks on file changes.

Some viruses can infect files without increasing their sizes or damaging the files. They accomplish this by overwriting unused areas of executable files. These are called cavity viruses. For example, the CIH virus, or Chernobyl Virus, infects Portable Executable files. Because those files have many empty gaps, the virus, which was 1 KB in length, did not add to the size of the file.

Some viruses try to avoid detection by killing the tasks associated with antivirus software before it can detect them.

As computers and operating systems grow larger and more complex, old hiding techniques need to be updated or replaced. Defending a computer against viruses may demand that a file system migrate towards detailed and explicit permission for every kind of file access.