A computer virus is a computer program that can copy itself and infect a computer without permission or knowledge of the user. It can spread to other computers and files whenever infected files are exchanged. Often infected files come as email attachments, even from people you know. The email senders have no idea that they are passing on a file with a virus in it. It may corrupt or delete data on a computer, use an e-mail program to spread the virus to other computers, or even delete everything on the hard disk.
There are many kinds of computer viruses, such as Macro Viruses which use commands (macros) that are embedded in other software to infect and spread to other files viewed by that software. Besides that, Worms can also duplicate themselves and use communications such as email to spread. On the other hand, File viruses also attach themselves to other software.
When the software is run, the virus first loads itself into memory so that in can further infect other files or begin damaging the computer. Moreover, Trojan Horses are programs that claim to perform a particular function but in fact do something different. Next, Backdoor Trojans are programs that allow other computer users to remotely control your computer via a local area network or the Internet. Besides that, Adware work through internet browsing. Adware often revolves around targeted advertising based upon the web sites you frequent and you may not even be aware that the pop-ups are not coming from the actual web site visited itself but from the Adware software running locally on your machine. Moreover, Spyware is software that tracks your actions and/or your Internet use. It can capture what you type on your keyword, including passwords, and send it to the spyware creator. Finally, Page hijacking is a form of search engine index spamming. It is achieved by creating a rogue copy of a popular website which shows contents similar to the original to a web crawler, but redirects web surfers to unrelated or malicious websites.
How it affect the computer performance?Malware programs can create many problems for the computer user. They will typically take up computer memory used by legitimate programs and often cause erratic behavior. In addition, many types of malware are bug-ridden, and these bugs may lead to system crashes and data loss. Many Control Impact Demonstration (CiD) programs are programs that have been downloaded by the user and pop up every so often and in turn slow down the computer.
There are some symptoms when a computer infected by the virus, includes the computer will stops responding, or it locks up frequently; the computer crashes, and then it restarts every few minutes; the computer will restarts on its own and does not run as usual; applications on the computer do not work correctly; disks or disk drives are inaccessible; cannot print items correctly; see unusual error messages; see distorted menus and dialog boxes; there is a double extension on an attachment that you recently opened, such as jpg, .vbs, .gif, or .exe; an antivirus program is disabled for no reason and cannot be restarted; antivirus program cannot be installed or can not be run; new icons appear on the desktop that you did not put there, and are not associated with any recently installed programs; strange sounds or music plays from the speakers unexpectedly; and a program disappears from the computer even though you did not intentionally remove the program.
How to protect your computer from virus?There are several ways to protect the computer from virus affections. The most useful ways was installing anti-virus software. Always make sure that it is always turn on and scanning the entire incoming message, email and file. Although until now, no virus scanner will detect every kinds of virus but they are able to detect the majority of common virus that affect the computer. So, makes sure your anti-virus program is always up-to-date to prevent the latest threats. The most important software to keep up to date is your Windows operating systems. It is essential to have Automatic Updates turned on and set to download and install updates automatically. Besides that, some anti-virus programs are able to scan opened files in addition to sent and received emails 'on the fly' in a similar manner. This practice is known as "on-access scanning". Meanwhile, the users also have to run the virus scan regularly at least once a week.
Other than install anti-virus software, we must also install only trusted software. Don't install some software which you not sure where it's come from. Sometimes programs will ask you to install other programs during the installation of first application. Be careful of this, because it is usually spyware. Thus, you are advice to install software from reliable sites only, such as Microsoft or Adobe. On the other hand, avoid P2P file sharing software. Although, P2P software is quite useful for movies, song and software, but if you're not very technically savvy, you might end up downloading a song that has a keystroke logger attached to it, that may be will send anything you type to some other computer over Internet.
Backups of all those important documents or files and store them to those file that are unconnected to the system or use other different file systems. Hence, if data lost through virus, we can start using the backup. It will protect all the files or documents from virus threats. Besides that, making backup will also protect your information against accidental file deletion, diskette failure or other damage. A notable exception to this rule is the Gammima virus, which propagates via infected removable media.
Next, to minimize the damage of virus, you should delete unknown emails. If you receive emails from someone you don't know, please do not hesitate to open the mail and just delete it. On the other hands, do not download or open any attachments unless you confirm that it's from someone you know. In common, most large companies that you create online accounts with will not send you any attachments, unless you specifically ask for them through their website.
Moreover, do not click on any advertisement, especially those which will pop up suddenly or flying around asking you to shoot on something to win some prize. Advertisement have become more wisely in that they try to make the advertisement interactive so that the people will tempted to play it like a game. Do not click on the link that people send you, especially when playing messenger. Some of the people when they affected by virus, their computer will automatically send to his or her contacts some link which contains virus. They will usually create some interesting name for the link to attract people's attention.
Another important step is the users have to be careful with what they attach to their computer. This is the most common way of transfer viruses, as no one will know when the viruses are on one of the computers and accidentally got transferred to their USB stick. A lot of virus programs will auto launch to the USB stick when it is put into the computer. It doesn't even need to open or download any of the files to be infected.
Moreover, for the users who running Window XP, please make sure that the Window Firewall is turned on. Firewall can prevent hackers from gaining access to your computer by limiting the number of ports that are open to the public. Besides that, when purchasing wireless router, make sure that it has built in firewall. Having a software and hardware firewall is better than just having one or another.
Lastly, you may use a complex password to login your computer to prevent hacker to hack in your computer system. User can make their password complex by having numbers, upper case characters, lower case character, symbols etc. This makes it more difficult for a hacker to get into your computer.
Type of Antivirus softwareNorton Antivirus is the most common antivirus software nowadays. The latest Norton antivirus 2009 provide fast, responsive defense against all types of malicious software. It can protect your system without slowing it down. Rapid pulse updates every 5 to 15 minutes, helps to ensure that you're protected from the latest threats. Working quickly and quietly in the background, Norton Antivirus only requires little memory and system resources. The new Norton Insight relies on extensive online intelligence to target only those processes at risk, resulting in faster, shorter, fewer scans.
Besides that, AVG antivirus is one of the famous antivirus software in the market. In the latest AVG antivirus version 8.0, its scanning features have been speed up and the new interface is a clean and modern take on a time-tested product. It also includes a link scanner and integrates AVG Antispyware and AVG AntiRootkit that provides an even more effective product. But, the on-access scanner stills tend to slow down computer to the point where they are not usable at times. Beyond to the slowdown issue, AVG Antivirus 8 is a complete product that will help keep your computer clean and safe.
Kaspersky Antivirus is the best antivirus software which has offering 99.9% of detection rates. It provides full protection for email, web surfing and all achieve formats and even checking itself to make sure its antivirus components have not been tampered with. Finally, Kaspersky offers daily updates and these updates are very small, only between 3 and 20kb. Kaspersky Antivirus automatically checks for viruses in all incoming and outgoing messages. The only negative way of this antivirus is they are not users friendly because the installing process is complicated.
How to solve computer if it is affected by virus?Autorun Virus Remover avoids any malicious programs which try to attack via USB drive. When a USB device is inserted into your computer, Autorun Virus Remover will automatically scan it, block and delete autorun virus, trojans, and malicious code. Moreover, it can also remove the autorun virus if you can't open your hard disk and USB drive (Pen drive, Memory card) by double clicking. Autorun Virus Remover USB antivirus software to permanently protect offline computer against any USB virus without the need for signature updates. This light and easy to use solution is compatible with all software and doesn't slow down your computer at all.
Trojan Remover aids in the removal of Trojan horses when standard antivirus software has failed to detect them or is unable to eliminate them. Trojan Remover was written to let you carry out a removal without having to manually edit the system files, including the Windows Registry. Trojan Remover also gets rid of the additional system modifications that some Trojan horses carry out, which are ignored by other antivirus and Trojan horse scanners.
Netcom3Ã¢ÂÂ¢ is a recognized global leader in internet security software. Netcom3 Internet Security Suite's key focus is on securing sensitive consumer online interactions, as well as prevent and remove Spyware, Adware, optimize, fix PC errors, and make your system run faster and error free. It can automatically detects and corrects the most common problems including: run time errors, corrupt files, invalid paths, fonts, file types, CLSID, DLLs, sound, help files, shell extensions, AppEvents, class keys and many more.
Lastly, reinstalling the operating system is another approach to virus removal. It involves simple reformatting the OS partition and installing the OS from its original media, or imaging the partition with a clean backup image. This method is simpler to do, and faster than running multiple anti-viruses scans, and is guaranteed to remove any malware. But, the disadvantage is has to reinstall all other software as well as the operating system.
ConclusionViruses are dangerous. Thus, you should know how to protect against them. However, there is no reason to panic over viruses. The media tends to make viruses seem like they can destroy your computer at any time, but this is not the case. You can maintain a relatively safe computer with a little bit of understanding and vigilance. Research any new viruses you hear about to make sure that the threat is real. If it is, make sure your virus scanner is up to date.
ReferenceComputer virus- Wikipedia, the free encyclopedia. Retrieved October 2008, from http://en.wikipedia.org/wiki/Computer_virusComputer Viruses. Retrieved October 2008 from http://www.online.tusc.k12.al.us/tutorials/viruses/viruses.htm#cvbasicsMarshall Brain (2008). HowStuffWorks "How Computer Viruses Work". Retrieved October 2008 from http://computer.howstuffworks.com/virus.htmComputer Viruses: What is a Computer viruses? / Microsoft Security. Microsoft Corporation (2008). All Rights Reserved, Retrieved October 2008 from http://www.microsoft.com/protect/computer/basics/virus.mspxComputer viruses: description, prevention, and recovery. Microsoft (2008). All Rights Reserved, Retrieved October 2008 from http://support.microsoft.com/kb/129972Computer virus: Definition form Answers.com, Answers Corporation (2008), All Rights Reserved, Retrieved October 2008 from http://www.answers.com/topic/computer-virusQUT | ITS | Virus & Spyware Protection | Types of Viruses, Retrieved October 2008 from http://www.its.qut.edu.au/virus/types.jspComputer Virus FAQ for New Users, Retrieved October 2008 from http://www.faqs.org/faqs/computer-virus/new-users/Protecting your computer from viruses, UW Technology, Retrieved November 2008, from http://www.washington.edu/computing/virus.htmlKaspersky Antivirus PersonalAntivirus Software Best Buy Reviewssoftware-antivirus.com. All rights reservedRetrieved November 2008, from http://www.software-antivirus.com/program/kaspersky-antivirus-review.html