Thurman said cyberattacks are "ideal" for North Korea because they can take place relatively anonymously. He said cyberattacks have been waged against military, governmental, educational and commercial institutions.
North Korean officials have not acknowledged allegations that computer experts are trained as hackers and have denied many of the cyberattack accusations. Pyongyang has not commented on the most recent widespread attack in South Korea.
In June 2012, a seven-month investigation into a hacking incident that disabled news production system at the South Korean newspaper JoongAng Ilbo led to North Korea's government telecommunications center, South Korean officials said.
In South Korea, the economy, commerce and every aspect of daily life is deeply dependent on the Internet, making it ripe grounds for a disruptive cyberattack.
North Korea, in contrast, is just now getting online. Businesses are starting to use online banking services, and debit cards have grown in popularity. But only a sliver of the population has access to the global Internet, meaning an Internet outage two weeks ago — which Pyongyang blamed on hackers from Seoul and Washington — had little bearing on most North Koreans.
"North Korea has nothing to lose in a cyber battle," said Kim Seeongjoo, a professor at Seoul-based Korea University's Department of Cyber Defense. "Even if North Korea turns out to be the attacker behind the broadcasters' hacking, there is no target for South Korean retaliation."
Associated Press writer Jean H. Lee contributed to this story with reporting from Pyongyang, North Korea; Hyung-jin Kim in Seoul also contributed to this report. Follow AP tech writer Youkyung Lee at www.twitter.com/YKLeeAP and AP Korea bureau chief Jean H. Lee at www.twitter.com/newsjean.
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