The choice of security anti-virus (if we disregard the issue of cost) depends on its quality requirements. If the use of Internet is not that active, only trusted web-sites from a limited list are visited, correspondence is only with a limited number of people and there are no tones of spam, new programs are not downloaded from the Internet – requirements to anti-virus protection can be minimal.
Otherwise, however, if the network is used extensively, the volume of email is high, and search services are used on a regular basis – requirements to quality and functionally of anti-virus protection are much higher.
Reliability and usability are the most important criteria, as even the ‘absolute antivirus’ might prove to be absolutely useless if it conflicts with the system, strongly reduces its efficiency or from time to time “hangs”. If an antivirus requires special skills which most common users are devoid of, it will be too difficult to use (work with). Common user will simply ignore its messages and randomly click «Yes» or «No», depending on which is closer to the cursor. And if an antivirus asks the common user difficult questions, most probably the latter will disable, if not delete the program from the system. If a corporate antivirus version does not have features required to administrate the company’s network, most system administrators will rather choose a product which would be less secure but more convenient.
Comprehensive protection is the second critically important criteria. All computer domains, all types of files and network elements which can be potentially attacked by a virus have to be constantly under protection. The program should be able to detect a malicious code and protect all channels of possible intrusion (e-mail, WWW, FTP e. t.c.), leading into the computer and the network.
Quality of protection is the third key criteria. Any most sophisticated antivirus is of no use is it is unable to provide a required level of protection from malicious programs. Anti-viruses have to resist a quite aggressive environment which is constantly developing – often new viruses, worms, Trojans become much more complex than their previous versions.
As for protection quality, it is made up of the following features: level of detection of malicious programs, frequency and regularity of updates, ability to delete the virus code from the system properly, resource capacity, possibility of double protection (systems) by different manufacturers, ability to protect not only from known – but also from new viruses and Trojans.