A PROJECT REPORT ON ANTIVIRUS 1.INRODUCTION “Antivirus (or anti-virus) software is used to prevent, detect, and remove malware, including computer viruses, worms, and trojan horses. Such programs may also prevent and remove adware, spyware, and other forms of malware.” Antivirus software is used to prevent, detect, and remove malware and other computer viruses. Anti virus software systems detections involve searching for known malicious patterns in executable code. it is possible for a user to be infected with new viruses that have no sign or symptoms or existence. To counter this problem of zero day threats, anti virus systems can be used to detect these viruses when you don't even know that they are there. TYPES OF COMPUTER ANTIVIRUS There are many different types of anti virus software that have been developed over the years. Original products were just scanners that would search through the hard disk looking for viruses. As viruses have become more common and difficult, the more anti virus software is being made to keep up with current virus issues. There are many different types of general virus scanners that are used on PCs today: Conventional Disk Scanner This is the stand virus check program. It can be ran upon the users request, and it scans the contents of the disks, directories or files that the users wants, for any boot sectors or files that contain viruses that it recognizes. These are usually ran manually by the user as a preventive maintenance activity or when they thing a virus is suspected. The user can schedule automatic scanning through the use of a program scheduler. Memory Resident Scanners An anti virus software that now come with a special program that sits in the background while your using your computer and it automatically scans for viruses based on different triggers. These programs can automatically scan as they run or scan floppy disks when you command a shutdown of your system. This scanner offers increased protection and more chances of catching a virus before it does damage to your computer. Behavior Based Detection Some products offer an option where they will sit in memory and look for virus like behavior and suspicious activity. Behavior based detection is looking for the types of actions taken on files or boot sectors that might be performed by viruses trying to spread. This type of antivirus software will look for a trap, and will generically catch viruses red handed. Start up Scanners This type of antivirus scanner is designed to be run every time the PC is booted up. It preforms a quick scan of the disks boot sectors and critical system files. the idea is to catch these viruses before the PC boots up reducing the chance of it to spread. Inoculation Instead of scanning for viruses this type of antivirus software looks for changes that the viruses make to files and boot sectors. With a clean system the software will get a snap shot of information in each boot sector about its content and size. Periodically it will re examine these files to see if anything has changed. Top Anti Virus Software The Shield Deluxe 2009 Antivirus & Antispyware Webroot Antivirus with Antispyware 6.0 BitDefender Antivirus 2009 CA Anti-Virus Plus 2009 McAfee VirusScan Plus 2009 Norton Antivirus 2009 ESET NOD 32 3.0 ADVANTAGES OF ANTIVIRUS Having a good anti-virus program can be the difference between the life and death of yourcomputer. With so many computer viruses in existence, protecting your computer's security should be one of your top priorities. Aside from just stopping viruses, most anti-virus programs have other features, such as firewalls, that will ensure the well-rounded safety and security of your valued computer. 1.Protection from Viruses The greatest and most obvious advantage to installing anti-virus software on your computer is that it will prevent you from getting viruses such as trojans, malware and spyware. Viruses range in severity from the harmless to the downright system crippling. Not only can a virus destroy all of the valued data on your computer, it can make the computer utterly worthless by infecting and destroying processes vital to your computer's performance. 2.Protecting Personal Information Hackers and viruses go hand in hand. A good anti-virus program will protect you while you surf the Internet, preventing hackers from gaining access to personal things such as credit card information and bank account access. The firewall feature included with most anti-virus software will block any unauthorized incoming connections to your network or computer, preventing hackers from digging their hooks into your life and your computer. 3.Cost Savings Though some anti-virus programs are quite pricey, there are some very good options for those wanting something relatively cheap or even free. Many free anti-virus programs are available that will protect your system just as well as a subscription-based anti-virus program. Even if you choose to go with a program you have to pay for, the cost of the program and subscription to their service will almost certainly extend the life of your computer, meaning you'll have to purchase new computers less frequently than those who choose not to use anti-virus software. 4.Convenience Though you may find it inconvenient to have to run virus scans and worry about the security of your computer, you'd have more to worry about without proper anti-virus protection. A computer left open for viruses and hackers will often start to show premature signs of wear and a significant slow down will be noticeable, making normal computing tasks take much longer and causing much more hassle. Let's assume your system does get infected with a virus. Without protection you'd be at the mercy of the virus and you'd have to waste time trying to find it, delete it and restore any damage it has caused and it will still probably be there, even after deletion. Yet with proper real-time anti-virus software working you will simply get a notification that a virus has been detected and be asked if you would like to delete it. These notifications usually come as soon as the virus is detected, leaving it without enough time to do its damage. WHAT IS COMPUTER VIRUS People have a very general view that there are many types of computer viruses and are those programs that cause damage or make the system crash. Malicious code is the general word used and virus is one type of malicious code. Worms and Trojans are different from computer virus and destructive types of worms are sometimes termed as internet types of virus. Computer viruses have made their mark on the PC's since the 90's with different types of viruses causing damage to computers. The earliest viruses made the most impact as no anti-virus programs were available. The advent of anti-virus programs spelled a death blow to many common types of computer viruses that were written by the various tools to generate types of computer virus. Those who were inept at programming used these various tool to generate the virus. Devious mind always find new ways when they found that the anti-virus software's were able to disinfect and remove the different types of computer viruses they went on to new methods and that is how Trojans and worms came up. There are a few main types of computer viruses and these computer virus types are classified below depending upon the infection methods: Boot sector/Master Boot Record Computer Virus Means of Infection Boot sector is that area of the computer that is accessed when the computer is turned on. A boot sector virus infects this portion. Once the boot sector is infected the virus is loaded into memory when the computer is turned on. This virus then infects boot sectors on floppies or other removable media Master Boot record virus only infects the Master boot record and not the boot sector Damage Caused Boot sector viruses gain complete control of the master boot record or the DOS boot sector by replacing the operating system contents with that of its own. This allows the virus to spread fast and cause damage: By gaining control of the master boot record and the DOS boot sector the boot sector viruses can sometimes hide the resources that the computer has( the floppy drive even though attached may not be present) Some boot sector viruses contain instructions to redirect disk reads. Some boot sector viruses move the master boot record to another location causing the system to crash when it boots up. Other boot sector viruses cause damage to the master boot record Some boot sector viruses damage the File Allocation Table (FAT) which is the index of all the files on the drive. This causes loss of data Removal The best way to remove boot sector virus is to boot the computer with using a clean boot disk and then rewrite the files with the good operating system files on the infected disk. These viruses were very much prevalent in the ninety's and a host of antivirus programs are now available to detect and clean them effectively HOW ANTIVIRUS PROTECT COMPUTER FROM VIRUS How many times have you been pestered with viruses, spywares, bad cookies and all sort of malware? How many times have you lost your important documents and pictures, because you clicked on a little file you got in your e-mail client? How many times have your computer stopped working normally after you visited a web-site? If your reply is “a lot of times” or “sometimes” then this guide is for you.