What is an antivirus software

Antivirus software consists of computer programs that attempt to identify, thwart and eliminate computer viruses and other malicious software (malware) Antivirus software typically uses two different techniques to accomplish this: * survey (scanning) files for viruses known corresponding definitions in a virus dictionary.* Identification of any suspicious behavior of a computer program which might indicate infection. This analysis may include data collection, port monitoring and other methods. Most commercial antivirus software uses both approaches, with particular emphasis on the virus dictionary approach. Historically, the term antivirus has also been used for benign proliferation of viruses and malicious software to combat viruses. This was common on the Amiga computer platform. Virus dictionary approach, when the antivirus program to check a file, refers to the dictionary of known viruses that the perpetrators of anti-virus software have been identified. If a fragment of a file matches any virus identified in the dictionary, the antivirus software so it can be one of the following actions:

• Try to repair the file by removing the virus from the file itself * quarantine the file (such as the file remains inaccessible to other programs and its virus can not spread) * delete the infected file to succeed coherent medium and long term, the virus dictionary approach requires periodic (generally online) downloads of updated virus dictionary entries. As civically spirit and technically inclined users identify new viruses "in nature, they can send their infected files to the authors of antivirus software, which then information about new viruses in their dictionaries. From a Dictionary of antivirus software reviews typically files when the operating system of the computer creates, opens, closes or e-mail. In this way, can detect a known virus immediately upon receipt. Note also that a system administrator can usually schedule antivirus software to examine (scan) all files on the hard disk of the user on a regular basis.Although the dictionary approach can effectively contain virus outbreaks in certain circumstances, virus authors have tried to stay one step ahead of such software by writing "oligomorphic", "polymorphic" or more recently "metamorphic" viruses, what the parties themselves to encrypt or not change as a method of disguise, so that does not match the signature of the virus in the dictionary. suspicious behavior suspicious behavior approach, by contrast, is not to identify known viruses, but observed the behavior of all programs. If a program tries to write data to an executable program, for example, the antivirus software may report this suspicious behavior, alert the user and asks what to do.Unlike the dictionary, the suspicious behavior approach therefore protects completely new viruses, which are not yet any virus dictionaries. But it can also play a lot of false positives, and users may become insensitive all warnings. If the user clicks on "Accept" in alarm, then the antivirus software obviously gives no benefit to the user. This problem has worsened since 1997, as many nonmalicious program designs came to modify other. exe, regardless of this issue false positives. It 's the most modern antivirus software uses this technique less and less. Other approaches Some antivirus software use other types of heuristic analysis. For example, you could groped to emulate the code at the beginning of each new executable that the system is based on before transferring control to that executable.
• If the program seems to use even modify the code or otherwise appears as a virus (if it immediately tries to find executables, for example) would suggest that the virus has infected an executable file. But this method can generate a lot of false positives. Another detection method involves using a sandbox. A sandbox emulates the operating system and run the executable in this simulation. When the program is finished, the software analyzes the sandbox for any changes that might indicate a virus. Because of performance issues that normally this kind of detection is only for on-demand scanning. Also this method may not be that viruses can not deterministic and lead to different actions or no action at all to do, then run - so it will be impossible to detect an execution.

Some virus scanners can also warn you if the file can contain a virus based on the type of file. E-mail virus problems from spreading their infection vector can be prevented more economically and efficiently, without having to install additional antivirus software, if the errors in the e-mail programs that allow unauthorized code sets. User education can effectively supplement your antivirus software. Simply training users in safe computing practices (such as not downloading and executing unknown programs from the Internet) would slow the spread of viruses and prevent a lot of antivirus software.

Computer users should always be run as an administrator of your computer. If you go to user-mode fault, then some virus may be distributed outside of your personal area of the system, when the operating system files and users have the same Mutch. Dictionary approach and identify the virus is not always enough - because of continuing new viruses - but the suspicious behavior approach does not work very well because of the problem of false positives, and therefore the understanding of anti-virus software will never conquer viruses.

There are various methods of encrypting and packing malicious software which will make even known viruses undetectable to antivirus software. Detecting these "camouflaged" viruses requires a powerful unpacking engine, which can decrypt the files before examining them. Unfortunately, the popular antivirus programs are not many who have not and therefore often unable to detect encrypted viruses. Writing today and the spread of viruses and panic about them gives the vendors of antivirus software business has a financial interest in the continued existence of the virus. Some theorize that antivirus companies have financial ties to virus writers to create their own market, although there is currently no evidence of that.

Some antivirus software can considerably reduce performance. Users can disable the antivirus protection to overcome the loss of performance, thus increasing the risk of infection. For maximum protection of anti-virus software must be activated at any time - often at the expense of lower performance. Some antivirus software has less impact on performance. It is often necessary to temporarily disable virus protection when installing major updates such as Windows Service Packs or updating graphics card drivers. Having antivirus protection running at the same time as installing a major update may prevent the installation of the update correctly or not at all.

When purchasing antivirus software, the agreement may include a clause that your subscription will automatically renew your credit card automatically billed at the time of renewal without approval. For example, McAfee requires one to unsubscribe at least 60 days before the expiration of the current subscription, but does not provide access to a telephone or a way to unsubscribe directly through their website. In this case, the use of the subscriber to contest the charges credit card issuer. History The first anti-virus software was created by Peter 1991.Tippett Tippett was a doctor in the emergency room, which also provided a computer programcompany. He read an article on the first computer virus is on the market (Brain, Lehigh and Jerusalem2 were the first viruses to grow, but it was Lehigh Tippett read) and asked them if their similar virus that infects humans. From an epidemiological standpoint, it has been able to determine how these viruses were affecting systems within the computer (boot sector has been hit by the virus Brain. COM files have been affected by the virus Lehigh and boats. COM and. Exe was influenced by the Jerusalem virus). Tippett Company Certus International Corp. then began to create anti-virus software. The company was sold in 1992 to Symantec Corp, and Tippett went to work for them, incorporating the software he developed the product in Symantec's Norton AntiVirus.\