What is a Computer Virus?
What is a computer virus? A computer virus is a program designed to compromise computer security and spread itself by first infecting executable files or the system areas of hard and floppy disks and then making copies of itself. Viruses usually operate without the knowledge or desire of the computer user and are a threat to data security. They also may slow down your pc or may corrupt specific files. Viruses often come through email messages but can also come from software installation or just from clicking on a website.
Automating your Virus Scanning
In addition to using internet security software to scan for viruses on a regular basis, install an ?on access? scanner (included in most good internet security software packages) and configure it to start automatically each time you boot your system. This will protect the information security of your system by checking for viruses each time your computer accesses an executable file.
What Will a Computer Virus do to my Computer?
Note that viruses can?t do any damage to hardware: they won?t melt down your CPU, burn out your hard drive, cause your monitor to explode, etc. Warnings about viruses that will physically destroy your computer are usually hoaxes, not legitimate virus warnings. You don?t risk your computer security by ignoring these warnings.
Exploit Computer Viruses
An "exploit" is a short piece of code or script that uses a computer security vulnerability in software or an operating system to perform certain malicious actions. The most famous exploit is called ?Incorrect MIME Header exploit? or ?Iframe?. The Incorrect MIME Header exploit allows one to automatically run an e-mail attachment on certain unpatched versions of Microsoft e-mail and web browsing software. This exploit is widely used by famous e-mail worms - Nimda, Klez, Yaha, Bugbear, Bridex and many others. When a recipient of an infected e-mail only previews an infected message, an infected attachment is activated by the Iframe exploit and a computer becomes infected.
Tips on Ensuring the Security of Your Computer
Just because your computer is acting strangely or one of your programs doesn?t work right, this does NOT mean that your computer has a virus. If you haven?t used a good, up-to-date internet security software anti-virus program on your computer, do that first. Many problems blamed on viruses are actually caused by software configuration errors or other problems that have nothing to do with a virus.
System Back Up
Ideally, serious information security demands that you back up your entire system on a regular basis. If this isn?t practical, at least backup files that you can?t afford to lose or that would be difficult to replace: documents, bookmark files, address books, important E-mail, etc.
Computer Viruses and Data Security
Viruses have the potential to infect any type of executable code, not just the files that are commonly called ?program files?. For example, some viruses compromise data security and infect executable code in the boot sector of floppy disks or in system areas of hard drives. Another type of virus, known as a ?macro? virus, can damage computer security by infecting word processing and spreadsheet documents that use macros. And it?s possible for HTML documents containing JavaScript or other types of executable code to spread viruses or other malicious code.
Computer Security and Trojan Horse Programs
Simply downloading a file to your computer won?t activate a virus or Trojan horse; you have to execute the code in the file to trigger the data security threat. This could mean running a program file, or opening a document or spreadsheet in a program (such as Microsoft Word or Microsoft Excel) that can execute any macros in the document. These macro viruses can compromise your windows security and therefore the security of your pc.
Computer Viruses
If your computer is infected with a boot sector virus, the virus tries to write copies of itself to the system areas of floppy disks and hard disks. Then the infected floppy disks may destroy the computer security of other computers that boot from them, and the virus copy on the hard disk will try to infect still more floppies. Some viruses, known as ?multipartite? viruses, can spread both by infecting files and by infecting the boot areas of floppy disks.
Virus Scanners
Make sure to use internet security software to run a Virus scan on any new programs or other files that may contain executable code before you run or open them, no matter where they come from. There have been cases of commercially distributed floppy disks and CD-ROMs spreading virus infections.
How do Computer Viruses Work?
Virus programs are not a threat to your information security or computer security until the you run the program containing it. When you execute program code that?s infected by a virus, the virus code will also run and try to infect other programs, either on the same computer or on other computers connected to it over a network. And the newly infected programs will compromise internet security as they try to infect yet more programs.
Computer Viruses and Their Effects
Viruses are software programs, and they can do the same things as any other programs running on a computer. The actual effect on information security or data security of any particular virus depends on how it was programmed by the person who wrote the virus. Some viruses are deliberately designed to damage files or otherwise interfere with your computer?s operation, while others don?t do anything but try to spread themselves around and compromise internet security. But even the ones that just spread themselves are harmful, since they damage files and may cause other problems in the process of spreading.
Fixing an Infected Computer
If you do get infected by a virus, don?t panic. Just follow the directions in your internet security software software anti-virus program for cleaning it. If you have backup copies of the infected files, use those to restore the files and your data security. Check the files you restore to make sure your backups weren?t infected. For assistance, check the web site and support services for your anti-virus software.