UNDERSTANDING HOW VIRUS WORKS

Basically computer virus is set of instruction which copies itself continuously as soon as it is executed. Computer virus occupies whole space in main memory (RAM) results in no space for executing other programs, thus system performance degrades drastically. This is general example of how virus works. Virus will not affect the system performance every time; it basically depends on what code the virus program has been written.

To understand the virus behavior we will create a virus for UBUNTU (UNIX) using C program. Look at the code given below, make the same in Ubuntu and run using the following steps.

#include<stdio.h>

int main()

{

system("gnome-terminal");

system("gcc filename.c");

system("./virus");

return 0;

}

It will not cause damage to your system. It is just simulating program for understanding the virus behavior.

 Steps to run virus:

1. Make the same C file with above code.

2. To Compile type “gcc  filename.c –o virus” in terminal.

3. To run type“./virus ” and look what happens.

You have to execute it once then look what happens. It will never stop executing until the whole space of memory is not occupied by it. We cannot stop the execution of this program. Because it will not leave space in main memory to execute other programs. Now we will look what happened after execution of this file shown in fig 1. 

Fig 1. output after running above code

Does Linux User Need Antivirus Software?

NOT REALLY, infecting a LINUX machine is pretty hard to do. The Linux operating systems are generally regarded as well protected but not immune from the viruses, Trojans, worms. There has not yet been a widespread threat of viruses for Linux machine as Microsoft Windows software faces.

BUT, the myth behind the concept that LINUX have fewer viruses because no one uses them and WINDOWS have been effected more because there is a large number of users, is absolutely wrong. The real fact is that Linux operating system has different structure and different updating policy which makes it absolutely different from Microsoft windows. That’s the reason the Linux operating systems are more secure than windows.

Now, let us take a look what actually makes Linux a virus free. Linux implements a multi-user environment where users are offered by privileges for different purposes which will help them to use the system but cannot change the major settings. To gain access over such major controls one has to gain access to the core of a Linux system and for that one need to have root access. And the Linux is well walled with the security and gaining root access is nearly impossible.

The other reason for this is downloading of software. If we look at a Window’s user, he downloads software from many different websites on the internet by trusting the administration of those sites that they had tried their fullest to make it with proper security. At the time of downloading, there is no verification of the file that user is getting was actually from the certified source or someone in the middle is serving the request.

But if we look at the Linux area, all the hardware drivers are included with the kernel. And as for software, all software is delivered in installation packages which are signed and during the time of installation those signatures are checked. If in case any package has been replaced with the pirated version of software then we will get an error warning of that.  

One more reason we can point out that when a security defect is found in Windows application, the vendor will update on their sites and the user has to discover that and has to update their software. On Linux, security updates are applied to all the applications so users become aware of it immediately and they can update it by clicking a button.

The most important is that Linux is open source still it’s more secure than Windows because there are many security researchers who constantly look after the total environment of Linux operating system. Having the source code open they can inspect the problems and fix any bugs occurred. While with windows we have to trust the vendor because the code is not available with anyone so changes and fixing the flaws become impossible.

BUT, it’s a common idea that no operating system is totally free from virus. But this is also totally agreed that LINUX is not so exploited as closed-source ecosystems like WINDOWS .The open nature of the Linux makes it to be less affected by the malwares.

So, after looking all the areas I can say that Linux is less vulnerable to all the malware attacks and provide much security to the systems and the information which it carries. So, it is much preferable to use.