Antivirus software (antivirus) – a program to detect computer viruses and infected files, as well as for prevention – to prevent infection of the operating system files or malicious code (Eg, through vaccination). To date, known to tens of thousands of different malicious programs. That led to the need for any anti-virus. Any software that has its admirers and opponents, sometimes bellicose with regard to both in terms of 'unloved' software, as well as against each other. The first most common anti-virus programs have appeared almost immediately after the emergence of viruses.
Now engaged in developing antivirus software big companies. As with the creators of viruses in this area also formed the original methods – but to find and fight viruses. Modern anti-virus programs can detect thousands of viruses, but none of them do not give 100% protection. Methods for detection of viruses and antivirus software usually uses two distinct methods to accomplish their tasks: Scan files to search for known viruses, the corresponding definition in the antivirus databases detection of suspicious behavior from any programs similar to the behavior of the infected program. The method of determining compliance viruses in the dictionary – detection, signature-based. The word signature – Eng.
signature, means' signature 'or you can say' characteristics, some ID. " Signature analysis is to identify the characteristics of each virus and the virus scan by comparing files with known characteristics, which make up the anti-virus database. This method, when the anti-virus software, browsing the file refers to anti-virus database, which made by the manufacturer with antivirus software.