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Viruses have already become the biggest curse of the internet world, affecting millions of internet users and other business communities. Hackers, Spammers- whatever names you choose to call them, these programmers termed as malwares, have sown the seeds of fear and doubt in the minds of the general internet users. Privacy and security are the most affected segments and to escape from the hassles of the viruses, Up-to-date anti-virus software is essential for all PCs, particularly those that connect to the internet. It helps to prevent viruses, worms and other malicious software infecting your computer. It scans new files and emails, and regularly checks existing files and folders for abnormal behavior. Computer viruses are a sickness that every computer user encounters sooner or later. In fact, viruses are just one example of a whole group of nuisance programs which are known as malware. Types of malware include, Viruses which like their biological counterparts, these are programs that infect a computer (by various methods) and then spread to other computers when infected files or disks are exchanged, Worms which are similar to viruses but are carried on the Internet and can spread from one computer to another by themselves, with no need for a user to assist the process by giving someone an infected file or disk, Trojans so named after the Trojan Horse of mythology, these are programs that pretend to be harmless and useful, but which in fact do something sinister, like plant a virus in a computer, Spyware that is nothing but a software that tracks your online activity or monitors your keystrokes and sends this information to a remote server, Dialers which are programs that are downloaded to your computer from a web page, which then steal money from you by dialing premium rate phone numbers, Hijackers which are little programs that are usually infiltrated on to your system via email or your web browser, which then hijack your browser settings by (for example) changing your default home page setting.
Viruses, worms and Trojans cause a nuisance just by spreading their infections, but most of them also do something else, known as the payload. The payload may be something innocuous, like displaying a message or changing the system colours, or it may be something destructive like deleting files or formatting the hard disk. This payload often isn't activated until the virus has infected your computer for a while (giving it a chance to spread) so the fact that you haven't noticed anything unusual doesn't mean your computer is necessarily in good health.
If your computer gets infected, whether the payload is harmful or not you want to get rid of the virus as quickly as possible, so as to remove the risk of it spreading to the computers of your friends and colleagues. The only sure way to get rid of a virus is to use anti-virus software. Some viruses can be removed manually, but different viruses need different removal methods and by the time you've found out the correct procedure a software virus scanner could already have done the job.
In a few cases, the virus scanner may not be able to cleanly remove a virus from a file, and the file may be left corrupt and unusable. In this case, your only option is to restore an uninfected copy of the file from software installation disks or a backup.
A good backup system is by far the best safeguard against losing data due to the action of a virus (as well as other disasters). But it must work hand-in-glove with the regular use of a virus scanner; otherwise your clean backup files could be replaced by infected ones before you realize your system has a virus. It's better to prevent a virus from infecting your computer in the first place, than have to remove one after it has. Therefore, it's worth paying close attention to virus prevention measures.
The best all-round system of protection is to install anti-virus software and enable on-access scanning (this is usually enabled by default.) This will work silently in the background, checking files for the presence of viruses. You need not worry about it until it detects a virus and raises the alert.
However, you must remain conscious of the need for virus protection to the extent of remembering to update your virus scanner regularly. These days, daily updates are not too often! New viruses are constantly appearing on the scene, and despite the claims of software vendors, virus scanners are not very good at detecting viruses they don't know about. Updating is the only way to maintain your virus scanner at top effectiveness by ensuring it knows about, and can detect, all the latest threats. Trusted and reliable anti virus programs include McAfee, Norton Anti-virus, AVG, PCCillin, Trend-Micro and many others. Anti-virus programs work on continuous updates of anti-virus definitions and thwart new viruses by managing to keep a few steps ahead of them.
Internet Security Threats
The Internet provides a wonderful means of exchanging information, but no one wants sensitive information on their computers to be stolen or destroyed. Hackers and worms are constantly on the lookout for computers with security vulnerabilities connected to the Internet. Unfortunately, whether it's due to a lack of knowledge, tight budget, or sheer laziness, too many of us don't protect our own data.
Common Hacker Exploits
Once a hacker finds a computer with open ports they probe further to see if software behind each open port contains buffer overflows, outdated software or misconfigurations.
If a hacker finds one of these vulnerabilities they may attack your computer. Here is a partial list of the things a hacker could do to your computer if it has vulnerabilities:
View Your Passwords - If a hacker has access to your computer they may have access to files stored on your computer where passwords are kept. Sometimes passwords are stored in normal text and sometimes they are encrypted. Either way, a hacker can probably crack the passwords you use on your system so they can continue to access your computer.
If you access your company network from home then this becomes especially dangerous. The passwords you type to access your company network may be stored on your home PC. A hacker may be able to break into your corporate network because your home PC was not secure.
Watch Everything You Do - If a hacker installs remote control software then you are no longer safe. Remote control software allows a hacker to view everything on your computer as you do. If you view your personal banking information on your computer then so does the hacker. Also, remote control software allows a hacker to record keystrokes typed into your computer. So your passwords are no longer safe and should be changed.
Install a Zombie - Zombie software allows a hacker to "make" your computer attack other computers on the Internet. Once Zombie software is installed on your computer you will not know it is running. If Zombie software were installed on your computer right now you could be attacking the website of a large corporation. The corporation will trace the attack back to your computer and you will plead ignorance. In European countries you are now liable for damages to others if a hacker is using your computer for attack purposes.
Copy Files From Your Hard Drive - If you have network shares set to READ for the group EVERYONE then a hacker may be able to copy your data. If you have personal accounting data or confidential files on your computer then a hacker may have already copied that data. Accounting software, word processing, spreadsheet, and most applications don't use good password encryption schemes. Most passwords for these applications can be cracked easily.
Copy Files To Your Hard Drive - If you have network shares set to READ/WRITE for the group EVERYONE then a hacker may be able to copy files to your computer. Why is that a problem? This is how hackers install remote control software. Or they may decide to copy viruses to your computer, or ruin the configuration of your computer, or store pornographic material for later browsing or whatever.