The attacks, which targeted the White House, the Pentagon, and the Washington Post, among other high-level institutions, are raising concerns that the long-simmering clash with North Korea is expanding into a dangerous new theater.

According to South Korea’s National Intelligence Service, the “cyber attacks appeared to have been elaborately prepared and staged by a certain organization or state.”

In that statement, North Korea was not specifically named, but the Yonhap news agency said the NIS had traced the attacks to North Korea or pro-Pyongyang forces.

Many analysts see the attacks as a test of the US government’s ability to deal with a coordinated cyber-attack.

In late May, President Obama unveiled the details of an ambitious new cyber-security initiative, which he said would gird the nation’s infrastructure against digital threats.

“We rely on the Internet to pay our bills, to bank, to shop, to file our taxes,” Obama said in a news conference.

“But we’ve had to learn a whole new vocabulary just to stay ahead of the cyber criminals who would do us harm – spyware and malware and spoofing and phishing and botnets.”

The attacks on networks here and in South Korea are the latest reminder that cyber-security remains a pressing concern in the 21st century.

They may also be a sign that North Korea has stumbled across a new way to provoke its neighbors to the South and its enemies to the West.

State Department spokesman Ian Kelly said today that the attack against the state.gov website is “ongoing” but “much reduced,” Bloomberg News is reporting.

Kelly said he could not speculate as to the identity of the attackers. “We’re investigating, but we can’t confirm the source of attacks yet,” he said.

If Pyongyang were behind the recent cyber attacks, it would mark another escalation in North Korean provocations against Washington and Seoul.

South Korea’s National Intelligence Service stated that such a coordinated attack was likely the work of a large organization or state. The NIS suspected North Korea or pro-North Korean supporters but currently has no hard evidence.

Despite North Korea’s low levels of computer technology and internet connectivity, Pyongyang has an extensive and capable cyber terrorism effort to provide asymmetric attack capabilities.

Something About Estonia’s cyber attack in 2007

In April and May 2007, hackers unleashed a wave of cyber attacks that crippled dozens of government and corporate sites in Estonia, one of Europe’s most wired countries.

Estonian authorities traced the so-called denial of service attacks to Russia, and suggested they had been orchestrated by the Kremlin — a charge Moscow denied.