Attack of the Zombie Computers Is a Growing Threat

In their persistent quest to breach the Internet’s defenses, the bad guys are honing their weapons and increasing their firepower.

With growing sophistication, they are taking advantage of programs that secretly install themselves on thousands or even millions of personal computers, band these computers together into an unwitting army of zombies, and use the collective power of the dragooned network to commit Internet crimes.

These systems, called botnets, are being blamed for the huge spike in spam that bedeviled the Internet in recent months, as well as fraud and data theft.