Research has found that 99 per cent of enterprise-level networks have a serious gap in their IT security defences.

According to FireEye, advanced malware and targeted attacks are easily evading traditional defences, such as firewalls, intrusion prevention systems, anti-virus and web/email gateways.

Analysis of malware infections, detected by its Malware Protection System, found that 99 per cent of enterprises have had malicious infections entering the network each week. Also, 80 per cent of the enterprises faced more than a hundred new cases per week.

A company report found that cyber criminals are using 'highly dynamic malware' to circumvent traditional signature-based defences, with 94 per cent of malicious executables and malicious domains changing within 24 hours.

The ‘top 50' malware families account for over 80 per cent of successful infections seen in the wild by FireEye, while the most prevalent attacks are fake anti-virus scams and information stealing malware.

Ashar Aziz, founder, CEO and CTO of FireEye, said: “Enterprises need to closely examine their current IT defence perimeter and see if advanced malware is entering their networks unimpeded, and determine if they need to add an extra layer of defence to cover this harmful and costly security gap.

“Advanced threats use a multi-stage infection cycle to maximise their chances to evade detection and successfully steal confidential information, particularly user credentials and intellectual property data.”