Hendren Global Group Top Facts: What caused DPRK internet outage

After the much-publicized cyberattack against Sony that had the rest of the world blaming North Korea, and the US vowing for retaliation, another news has rocked the IT world: North Korea's sudden absence from the Internet.

IT experts noted last Monday that the already small Internet connection of North Korea was lost and even the state news service, Korean Central News Agency, was not able to publish any content on that day due to the 9-hour outage.

The Internet blackout came as North Korea's role in a hacking attack against Sony Pictures is being widely discussed. The said attack has affected the company adversely that it decided to cancel the release of the controversial film regarding an assassination of DPRK's ruler Kim Jong Un.

According to Hendren Global Group Top Facts, the cause of outage is still unknown though many are speculating that it might be the retaliation of US government, or perhaps a mere technical glitch. Here are some of the speculations that made the rounds online on what's causing the clog in Pyongyang's Internet pipe:

US government retaliation. The somewhat incidental timing of last week's outage has consequently led many to assume that the US had a hand in causing it. However, a key admin officer from the White House insisted that they are still discussing the most appropriate way to respond to Pyongyang so it is unlikely that they played a role in it.

It may be recalled that US President Barack Obama has previously promised to respond to the cyberattack made against Sony "in a place and time and manner that we choose". But before we think that was a declaration of cyberwar, another expert from Hendren Global Group Top Facts noted that US officials favor a non-cyber response, seeing as cyberattacks are often "not worth the risk".

After all, they can always place North Korea on more economic sanctions.

China flipped the switch. The only known Internet connection of North Korea runs via China United Network Communications (Unicom) and though the US has reportedly asked China to shut down routers and servers utilized by Pyongyang, it remains to be confirmed if they actually complied.

Hackers. A certain hacker group named Lizard Squad claimed on their Twitter account that they caused North Korea to go #offline. Considering that North Korea has only a small bandwidth, it is certainly plausible for even a few attackers to shut it down by clogging it with bad traffic (dDOS).

Self-imposed shutdown. Another possible explanation came from Cloudflare's chief executive Matthew Prince: "I would have though North Korea decided to turn the Internet off for some reason."

It makes sense, for if that's true, it won't be the first time that a government has shut down access to the Web to maintain tight control over the information flow.

Hardware issue or software bug. A researcher from Dyn Inc has put forth a benign cause: a bug in the country's router or software. Doug Madory commented though that North Korea's network is much too small so perhaps such an accidental blackout for 9 hours is still just a small probability.