Some Internet sites were back online Monday night after blanket outages across North Korea that lasted at least nine hours, according to U.S. analysts.
The secluded nation's links to the Internet were tenuous before the reported shutdown; Pyongyang does very little commercial or government business online, and most North Korean citizens do not have access to online services.
The White House would not comment on the issue Monday. A State Department spokesperson said of the federal government's responses to North Korea, "some will be seen, some may not be seen."
Doug Madory, an Internet analysis expert, told media that connectivity issues in North Korea began on Friday, and became progressively worse over the weekend.
"North Korea's totally down," he said.
‘‘I don’t know that someone is launching a cyber-attack against North Korea, but this isn’t normal for them. Usually they are up solid. It is kind of out of the ordinary. This is not like anything I've seen before."
Madory says that the outage seemed to be consistent with a DDoS attack, in which attackers flood a network with traffic until the servers collapse. While Madory says that maintenance problems could be a possible cause, it is unlikely that technical glitches could account for such a widespread issue.
An internet company out of San Francisco, CloudFlare, described North Korea's Internet access as "toast."
While the US government hasn't taken credit for the attack, North Korea's Internet outage does follow Obama administration requests to China for help in blocking North Korea's cyberattack capabilities.
Security experts are stressing that the blackout could have several possible causes, and that no one should be rushing to put blame on the U.S. government.
A DDoS attack resembles the kind of "cybervandalism" that Obama criticized just days ago following the Sony hack, and could possibly be a strategy more likely to be implemented by vigilante hacker groups. It's also possible that North Korea powered down their own systems, to prepare for any kind of retaliation that may come their way.