SEOUL, South Korea -- North Korea released a statement Sunday that clearly relished a cyberattack on Sony Pictures, which is producing an upcoming film that depicts an assassination plot against Pyongyang's supreme leader. While denying responsibility for an attack last week that disrupted Sony's computer system and spewed confidential information onto the Internet, an unidentified spokesman for the North's powerful National Defense Commission acknowledged that it "might be a righteous deed of the supporters and sympathizers" of the North's call for the world to turn out in a "just struggle" against U.S.