Businesses need to make sure that they not only have systems in place to stop spam e-mail infecting their PCs but also to ensure they are not responsible for sending spam in the first place, one firm has warned.

Graham Cluley, senior technology consultant at Sophos said that spam generated by the Storm (or Dorf) Trojan - a kind of virus that appears to be safe but is not - was responsible for four per cent of all e-mail traffic in January.

The virus usually comes in an e-mail relating to a current news event, but once open it infects a PC and then uses that computer to send more messages.

And with new versions of the virus being developed all the time, it was "imperative that all businesses ensured their spam and anti-malware solution" were up-to-date.

He explained that unless people ensured they were protected against this kind of attack then "the entire internet community" would suffer.
Research by Websense found that 45 per cent of businesses have had their IT systems infected by a virus in the past year.

According to a recent survey by Connect, the two biggest IT headaches for businesses were 'everyday hassles with IT' (37 per cent) and 'security concerns'