Cyber attack IP addresses in Austria, Georgia, Germany, South Korea and the U.S.

South Korea said Friday it had identified and blocked five IP addresses used to distribute computer viruses that caused a wave of Web site outages in the U.S. and South Korea.

South Korean and American officials have said they believe North Korea was behind the attacks, but none of the blocked Internet Protocol addresses were for computers in North Korea. They were in Austria, Georgia, Germany, South Korea and the U.S., an official from the state-run Korea Communications Commission said. (The official added that South Korea also blocked another 86 IP addresses in 16 countries that were used to spread different viruses that damaged hard disks or files in computers they contaminated.)

The latest evidence does not clear North Korea of involvement. It is likely that the hackers used the identified IP addresses to cover themselves, accessing the computers from a remote location.

U.S. officials have said some IP addresses have been traced to the North. The Yonhap news agency, citing an unnamed participant, said the spy agency told lawmakers that it suspects a technology research unit under the general staff of the North's military is behind the cyber assaults. (The NIS declined to confirm the report.) The Chosun Ilbo reported Friday the North has between 500-1,000 hacking specialists.