US, S. Korean websites under attack; N. Korea blamed

So it's cyberwar.

In a July 4 attack that is believed to come from North Korea or its sympathizers, the websites of a number of U.S. and South Korean government agencies were knocked out and experienced continuing problems since the holiday, the Associated Press is reporting today.

U.S. agencies having problems: the Treasury Department, the Secret Service, the Federal Trade Commission and the Transportation Department. The Washington Post and other private-sector sites were hit as well.

South Korea's National Intelligence Service told Korean lawmakers that North Korea is behind the distributed denial of service attacks.

Stateside, the U.S. Computer Emergency Readiness Team issued a notice "advised (agencies) of steps to take to help mitigate against such attacks," a Homeland Security spokesperson said.

The Transportation site was down Saturday through Monday; FTC was down Sunday and Monday. Ben Rushlo, director of Internet technologies at Keynote Systems, said the Transportation Web site was "100 percent down" for two days, AP reports. FTC was coming back online Sunday but by Tuesday was 70 percent unavailable.

Web sites of major South Korean government agencies, including the presidential Blue House and the Defense Ministry, and some banking sites were paralyzed Tuesday. An initial investigation found that many personal computers were infected with a virus ordering them to visit major official Web sites in South Korea and the U.S. at the same time, Korea Information Security Agency official Shin Hwa-su said.