N.Korea ruled out as computer hackers
Cybersecurity experts say U.S. officials have largely ruled out North Korea as the origin of a computer attack last July that took down U.S. and South Korean government websites.
But authorities aren't much closer than they were a year ago to knowing exactly who did it - and why.
The crippling strikes did not compromise security or breach any sensitive data, and experts say federal agencies are better prepared today.
The threats from computer-based attacks are increasing - and those attacks not only can disrupt service but they also can heat up political tensions.