Monday, June 22, 2009

Virus of Computer, what kind of Virus???

Computer viruses have come a long way since their first appearance in the 1970's. As pieces of programming code, they're written to perform a specific function. Viruses can spread through email attachments, application programs on your computer, or application programs installed from disk drives.
This species can copy itself and infect a computer without the permission or knowledge of the owner.
The effects a virus can have on your computer depends on how its been programmed to spread. Programming can be one of two types: resident and nonresident. Nonresident viruses are made up of two processes -one finds files on your computer to infect, and the other duplicates the virus within the files that have been found.

Resident viruses are made up of one process. It's sole function is to duplicate itself throughout your computer system. To do this, resident viruses are programmed to load into the computer's memory. By doing this, the virus itself is activated every time you turn your computer on. This process allows the virus to remain active and spread to other targeted applications on your system for as long as the computer is on.

The term "computer virus" is sometimes used as a catch-all phrase to include all types of malware. Malware includes computer viruses, worms, trojan horses, most rootkits, spyware, dishonest adware, crimeware, and other malicious and unwanted software), including true viruses. Viruses are sometimes confused with computer worms and Trojan Horse, which are technically different. A worm can exploit security vulnerabilities to spread itself to other computers without needing to be transferred as part of a host, and a Trojan horse is a program that appears harmless but has a hidden agenda. Worms and Trojans, like viruses, may cause harm to either a computer system's hosted data, functional performance, or networking throughput, when they are executed. Some viruses and other malware have symptoms noticeable to the computer user, but many are surreptitious.

How to prevent our PC from virus?
Nowadays, computer systems are built to protect themselves against viral infection. The floppy disk drives are quickly becoming a thing of the past, so this point of entry has become less popular. Macro viruses rely on security holes within programs like Microsoft Office, so the newer versions of these programs are less vulnerable, but can still be infected. Email viruses are the ones that are most likely to get inside your system.

The best practice is to not open any email attachments from people you don't know. Email attachments from people you do know should be approached with caution if they're worded strangely, or if you've no reason to expect an attachment from a particular person. And lastly, always keep an updated version of anti-virus software on your computer. A good anti-virus program will not only monitor your system, but will screen incoming emails for suspicious content.

Resource: Wikipedia,
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