There will come a day when these people cannot keep on top of all the viruses

Sal Viveros, McAfee

Sal Viveros, a spokesman for McAfee, said the contradiction between claims of preparedness and damage done showed that many companies only worried about the malicious programs when they had to.

Mr Viveros said that the research revealed that few small companies employed someone full-time to protect their network.

Instead, he said, the security job fell to those that oversaw the running of the whole computer network.

These people were usually so overworked that they only worried about security when something went wrong or a virus struck, he said.

Getting harder

The research revealed that only a third of businesses updated their anti-virus software daily. Others do it weekly (30%), monthly (10%) or only when there is a big outbreak (5%).

"Many are coping with the fire now," said Mr Viveros. "They are not being very proactive about security."

Big virus outbreaks force people to tighten security

Unfortunately the job of protecting a network was only going to get harder, he said. Figures collected by ICSA Labs show that the number of viruses in circulation and the number of machines being infected is constantly climbing.

"There will come a day when these people cannot keep on top of all the viruses," said Mr Viveros.

As viruses got smarter they became harder to protect against and more of a headache for anyone charged with securing a computer network, said Mr Viveros.

"It does not take someone to respond to an e-mail anymore," he said. "These things look for vulnerabilities all by themselves."