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Sunday, October 10, 2010

virus and antivirus


What is computer virus? 





Computer viruses are small software programs that are designed to spread from one computer to another and to interfere with computer operation.
A virus might corrupt or delete data on your computer, use your e-mail program to spread itself to other computers, or even erase everything on your hard disk.

Computer viruses are often spread by attachments in e-mail messages or instant messaging messages. That is why it is essential that you never open e-mail attachments unless you know who it's from and you are expecting it.
Viruses can be disguised as attachments of funny images, greeting cards, or audio and video files.
Computer viruses also spread through downloads on the Internet. They can be hidden in illicit software or other files or programs you might download.
To help avoid computer viruses, it's essential that you keep your computer current with the latest updates and antivirus tools, stay informed about recent threats, run your computer as a standard user (not as administrator), and that you follow a few basic rules when you surf the Internet, download files, and open attachments.

Once a virus is on your computer, its type or the method it used to get there is not as important as removing it and preventing further infection.

The Cure (antivirus)

Antivirus software is used to prevent, detect, and remove malware, including computer virusesworms, and trojan horses. Such programs may also prevent and removeadwarespyware, and other forms of malware.

A variety of strategies are typically employed. Signature-based detection involves searching for known patterns of data within executable code. However, it is possible for a user to be infected with new malware for which no signature exists yet. To counter such so-called zero-day threats,heuristics can be used. One type of heuristic approach, generic signatures, can identify new viruses or variants of existing viruses by looking for known malicious code in files. Some antivirus software can also predict what a file will do if opened by emulating it in a sandbox and analyzing what it does to see if it performs any malicious actions. If it does, this could mean the file is malicious.

Top 10 antivirus 2010
However, no matter how useful antivirus software is, it can sometimes have drawbacks. Antivirus software can degrade computer performance. Inexperienced users may have trouble understanding the prompts and decisions that antivirus software presents them with. An incorrect decision may lead to a security breach. If the antivirus software employs heuristic detection (of any kind), success depends on achieving the right balance between false positives and false negatives. False positives can be as destructive as false negatives. Finally, antivirus software generally runs at the highly trusted kernel level of the operating system, creating a potential avenue of attack.

In addition to the drawbacks mentioned above, the effectiveness of antivirus software has also been researched and debated. One study found that the detection success of major antivirus software dropped over a one-year period.


software virus that i used

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