Botnets beware: research detects spamming attacks.

• Position: TECH TALK

* Researchers at Microsoft have developed a system to detect botnet attacks on Web email providers.

Botnets are composed of computers that have been taken over by an entity without the owner's knowledge. These "zombie" computers are then commandeered to attack other computers and servers. Spamming botnets sign up for numerous Web site-based email accounts and then log in to send spam.

New software called BotGraph harnesses cloud-computing models and a graph-based approach to detect malicious activity spawned by spamming botnets. To catch them, BotGraph examines user activity logs of email accounts and produces large-scale graphs that assist in differentiating legitimate users from fake users.

"We looked at the graphs to analyze the similarities between the users. Each botnet-created fake user account in this graph will look very connected to each other," says Fang Yu, one of the researchers on the Silicon...