Antivirus Software How it Works

Antivirus software to scan the contents of computer hard drives in two ways. If there are known viruses (ie viruses known to exist and the antidote has been found) then the software will look for the signature (mark) virus - which is a unique string of bytes that identify a virus program is like a virus fingerprint - and will dispose of from your system. Most scanning software does not just look for the early type virus, but also can search for variants of these viruses, because the code of the virus signature is usually similar.

In the case of a new virus that has not found its antidote, anti-virus software will run a heuristic program that searches for virus-like activity on your system. When the program saw no symptoms of anything wrong, it will quarantine the troubled program and will display a message warning you about what will be done by the plan (eg changing your Windows registry). When you and the software felt that the program is a virus, you can send a file that has terkarantina at antivirus software vendor to be analyzed, determining signaturenya, calling it and put it in the catalog, and send her an antidote. The virus is now known viruses.

If the virus does not appear again - this often occurs because the virus is not well written to be distributed - the vendor would categorize it as a dormant virus (the virus to sleep). But some viruses spread like an earthquake: Distribution initially was always accompanied with the occurrence of aftershocks. Variants of the virus (the virus tracing the spread of the virus that emerged after the first) will increase the number of existing viruses.

An example is when the Melissa virus appeared in the United States LoveLetter, variant - VeryFunnyJoke - directly appear in a few moments, followed by more than 30 other species in two months later. And not all the variants derived from the mysterious author of the program. Some companies never infected by variant viruses that spread by the employees themselves are curious to the virus which they are received, creating variants, and release them in their company's computer system - sometimes accidentally, sometimes they want to do it.

Source: http://www.infokomputer.com