Computer security: networks face new email-related threats.

• Author: Marshall, Jeffrey
• Position: BusinessBRIEFS

Talk of a "zombie network" might trigger thoughts of B-movie classics like "Night of the Living Dead." But to email protection experts, a zombie network is nothing even faintly amusing: it's one of the latest and most threatening ways of corrupting corporate networks.

Such zombie networks are created through a partnership of email spammers and software virus writers, says Marc Borbas, product manager for Sophos, a British-based company specializing in anti-virus and email protection. Once a specific computer in a network has been infected, it becomes a zombie--in this case, he says, it becomes "an emailing machine that spammers can tap back into." These individual machines can be linked into a "network" designed to evade filtering technology. "These can bypass a lot of systems that look at the sender," Borbas says.

Looking at other concerns in network protection and security, Borbas mentions the illegal exchange of classified or customer data, some of it inadvertent. "Our approach is that [controlling this] is a filtering job," he says. Sophos, for instance, monitors both inbound and outbound email traffic, looking for keywords, types of documents, file extensions...