The growth of information technology particularly the internet has enabled easy and faster transfer of information. However, people with wrong intentions have taken advantage of this and developed threats that are bent on infecting users computers. Many organizations as well as individuals have invested huge resources in internet security systems such as anti-virus software to counteract the effects caused by viruses, worms, spam, Trojan horses and other forms of threats. Despite the use of these anti-virus software, advanced malicious codes are being developed almost on a daily basis that are able to infiltrate the anti-virus engine and cause extensive damage to the system.

The success of the threats can be attributed to the reliance on single anti-virus engine that are not able to quickly detect and respond to new threats as they occur. The success of any anti virus engine in protecting the organization’s network against attacks is its ability to get updated engine signature files-anti virus files that identify viruses present in the system. The most used way of spreading viruses or threats is through emails, which are able to spread quickly and can cause extensive damage to the network. Thus it will be crucial for the anti virus signature files to react fast to the new threats.

With most anti virus programs, there is a substantial delay between the time a new virus is released and when the signature files are updated to counteract the threat. It is a fact that there will be less chances of the system being infected, if the updated signature files are released quickly. Though anti virus companies claim to respond fast to new threats, there is usually a time difference between the response time of one company and another. A company may release signature files within hours of the detection of a new threat but may take even longer to release updates for other threats.

Each anti virus program operates differently by making use of a mix of technologies such as signature files, heuristics and sandboxing in fighting computer threats. Though some virus engine combines these technologies, there is no single virus engine that will offer 100% protection. Even if the response time of the virus engine is fast, there is no guarantee it will be fast the next time a new threat appears. Certain threats have been known to penetrate flawed virus engine updates that are hurriedly released and thereby cause extensive computer damage. Using one anti-virus engine will not be effective since viruses may bypass the flawed anti-virus program, while multiple anti-virus programs are likely to offer more protection. Thus to offer the highest possible security, multiple virus engines should be used.