CSEIT172132 | Received: 19 Feb 2017 | Accepted: 28 Feb 2017 | January-February-2017 [(2)1: 236-240] International Journal of Scientific Research in Computer Science, Engineering and Information Technology © 2017 IJSRCSEIT | Volume 2 | Issue 1 | ISSN : 2456-3307 236 A Comparison study of Computer Virus and Detection Techniques Soumen Chakraborty Department of Information Technology, MCKV Institute of Engineering, MAKAUT, West Bengal, India csoumen88@gmail.com ABSTRACT The virus is a kind of program which seriously infects the system, large organizations nowadays have big data to maintain which are spread to various locations in the world. As a result, security is a major issue for all companies nowadays. The data is the ultimate asset for any people nowadays. Which needs various precautions to maintain to keep safe those assets. As there is growing the popularity of various kind of virus like malware,trojan,hackers,adware it is really becoming a challenge to keep the system secure.With the growing popularity of internet in our daily lives, the risk of various kind of threats is also increasing day by day. There is various kind of virus also various kind of mechanism to catch that virus which needs proper analysis.In this paper, there is a small survey of various kind of virus detection methods along with their consequences it does to the system.That will help to understand the merits and demerits of each virus after the survey.At the end, there is a conclusion and some information on what can be done to keep away from the virus in a large virtual world. Keywords : Virus, Virus Detection, Signature-Based Virus Detection, Anomaly-Based Detection, Trojan 1. Details about Computer Virus The Computer virus is a program which has the ability to replicate itself without anyone intervention and after that, the replicate program can replicate further,the same process goes on and on[2].As a result, the harmful code is a program which refers to something which function against the specification mentioned[3].There are many kinds of malicious code or programs which are designed to do some illegal or unauthorized functions which are really harmful to the system.There are many kinds of malicious software which are typically known as worms,trojan,malware etc a kind of virus.A computer virus contains three kinds of subroutines.Just like a normal virus causes the disease to our body similarly computer viruses are coded to propagate into the system without leaving the sign of the virus into the system.The virus affects the system by attaching with the other system programs like some application software.So sometimes when computer boots it enters into the system as it also affects the hard drive or boot media.Those are really deadly kind fo virus.The most serious effect it does when it controls some part of application like the browser,changes its settings,changing the system date,which sometimes difficult for a user to track the problem,sometimes virus delete a large amount of data also,in worst case modifying or crashing the whole system.There are many kinds of viruses.Viruses work like parasites which infect the systems.These programs are in the form of .exe file or .com file that controls another program.When someone clicks the .exe file in the computer ,the virus affects the system sometimes crashes the whole system which needs to be formatted again. 1.1 Boot sector virus There are many formats of boot sector viruses are available.They are in major number as compared to all kind of computer viruses.Most risky computer virus till now.One of the popular boot sector virus is Michelangelo.They are difficult to detect.This kind of virus doesn't affect the normal performance of the computer always but silently it affects the removable media like floppy disks.The virus controls the system when the bootable media loads, as a result, the virus control the system before the operating system loads.it