Army of zombies invades China

China's rapid Internet growth has brought with it a somewhat disturbing side effect: multiplying zombies up to no good.

Zombies, or Internet-connected computers infected by worms or viruses and under the control of a hacker, are used to launch denial of service (DoS) attacks, or send spam or phishing e-mails. An average of 157,000 new zombies are identified each day, and 20 percent of these are in China, security company CipherTrust  reported this week.

"It shocks me that the numbers are so high," said David Stanley, CipherTrust's vice president and managing director for Europe, the Middle East, and Europe.

CipherTrust analyzed e-mails collected throughout March and the first half of April from customers worldwide. It found that 57 percent of spam originated from the U.S., down from 86 percent during June and July last year.

The decrease in spam from the U.S., and increase in zombies in China, was not necessarily a surprise, Stanley said.

"Criminals look for a weaker link, so places like China, or anywhere behind the U.S. in terms of computer literacy, are a good target," Stanley said.

China's fast-growing Internet population is also an attraction, he said. As of January, there were 94 million Internet users in the China, up 18 percent from the year before, according to the China Internet Network Information Center (CNNIC).

Hackers are moving their spam-sending efforts to emerging markets that don't have as many Internet security measures in place, or high levels of user education, Stanley said.

South Korea is the second-largest source of spam, delivering almost 16 percent of unwanted e-mail, CipherTrust said. That figure is up 13 percent from eight months ago, it said.

To thwart an army of zombies invading their countries, emerging markets should try to learn quickly from the U.S. how to educate and protect Internet users, Stanley said.

"It's very important that we learn from experiences we've seen in other areas," he said.