More than 295,000 virus-infected emails were sent to companies in the UK in May before anti-virus vendors could issue signature updates, according to email filtering firm BlackSpider Technologies. It"s long been known that there is a "window of exposure" - the interval between when a virus begins spreading and signature updates are issued by anti-virus vendors. BlackSpider has put a figure on this phenomenon in order to back up its argument that there"s a high risk of infection during this "window of exposure" for firms that rely on conventional anti-virus scanners alone.
Vendors that make most of their money from desktop or server-based anti-virus scanners argue that most of these viruses could be thwarted by a policy of blocking executable attachments in email. They also argue - with some justification - that many instances of virus infestation occur because people don"t keep anti-virus protection up to date and that older viruses pose the greater problem. Furthermore looking at virus-infected emails – rather than figures on virus-infected PCs that are harder to obtain – slews stats towards newer, chattier viruses. Desktop anti-virus protection also defends against viruses that propagate using browser exploits, unlike email filtering services.