SME owners should warn their employees about the danger of opening e-cards - even if they appear to be legitimate Valentine's greetings.
David Emm, senior technology consultant, explained that there was a "potential danger" attached to anything that was received via e-mail.
He said that while e-cards are "great in one sense" they could cause problems for an SME's IT net work.
Mr Emm said: "The problem is that some of the malicious mechanisms or ways of doing this [transmitting viruses] can look very, very legitimate. We've been tracking particular Valentine's Day activity over the last couple of days, and the Disney characters and cartoon characters and the whole thing … looks legitimate."
He said that people running an SME should tell their staff to be alert over this sort of email.
According to some reports there were five times as many different kinds of malware in circulation in 2007 compared to the previous year.
