Who is Behind the Cyberattacks on South Korea?

One day after the the massive cyberattack on South Korea, the biggest question everybody is asking is: who did it?

The answer, as usual in these cases, is uncertain. For lack of evidence, the most security experts, reporters, and observers can do is offer educated guesses. And in this case, the first, and most obvious, educated guess was to point fingers at North Korea. The South's historic enemy is still the main suspect, even after Internet security analysts announced on Thursday that the attacker's IP addresses traced back to China

That assumption isn't too misguided. The communist regime of the north and its southern counterpart have been entangled in a rhetorical scuffle for the past few weeks and diplomatic tension has been rising, with North Korea accusing South Korea and the U.S. of conducting cyberattacks against its network last week. Also, according to persistent rumors, both countries have operational cyberwarfare units. And there have been at least four cases in recent years when cyberattacks on South Korea were blamed on North Korea.