The Federal Bureau of Investigation said last week that it has identified more than 1 million captive computers.
Tracking "zombie" computers—those taken over remotely and forced to send out spam, spyware or denial-of-service attacks—presents a challenge for law enforcement, according to Shawn Henry, deputy assistant director of the FBI's Cyber Division.
Some IP addresses can be tracked to an individual, Henry says, but others cannot be tied to an active user.
And security analysts have discovered bots working inside corporations. Network security firm Support Intelligence has posted the names of more than a dozen companies with bots operating within their walls.
Henry says the private sector needs to update security software and policies to keep bots out of their networks. But how can companies defend against bots? The first thing CIOs and security executives need to know is how bots operate.
Check out the slide show below for a step-by-step look at how bot herders infect computers.
Slideshow: How Bots Attack—and How to Defend
Blog: Bots Found Inside Many Big Companies
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