North Korea's internet was hit by the largest outages in months on Thursday, a cybersecurity researcher told Reuters, after similar service interruptions in January were blamed on suspected cyber attacks.
Internet access is strictly limited in North Korea. It is not known how many people there have direct access to the global internet, but estimates generally place the figure at a small fraction - well below 1% - of the population of about 25 million. Many more have access to internal networks that don't connect to the outside world.
At least two waves of outages struck the isolated country's internet over a period of roughly 2.5 hours, peaking with surges in network stress that made North Korea's entire internet unreachable, said Junade Ali, a British cybersecurity researcher who monitors a range of different North Korean web and email servers.
"This isn’t like a single web server is being taken offline," he said, citing monitoring records that he shared with Reuters. "The network stress is so great their Domain Name System (DNS) servers have been taken offline and eventually the key routers allowing traffic in and out of the country entirely."
North Korea’s Ministry of Foreign Affairs website and Naenara, which is the official portal for the North Korean government, appeared to see the brunt of the suspected attack, before it became so great the entire internet was taken offline, Ali said.
Other major websites affected included the Air Koryo national airline and major internal email servers.
Up to 7 million North Koreans use cell phones daily, and WiFi networks have sharply expanded in recent years as the mobile devices increasingly became a key tool for market activity, though most do not connect to global networks, U.S. researchers said on Tuesday.
Like the suspected attacks in January, Thursday's outages come amid increased missile launches and other military activity by the North, which has drawn condemnation from the United States and its allies.
North Korea fired a ballistic missile on Thursday as it warned of "fiercer military responses" to U.S. efforts to boost its security presence in the region with its allies, saying Washington is taking a "gamble it will regret".
Researchers have said such outages show signs of being what they term distributed denial-of-service (DDoS) attacks, in which hackers try to flood a network with unusually high volumes of data traffic in order to paralyse it.
"From my experience and what I’ve seen before from monitoring their networks, I’d be surprised if this wasn’t an attack," Ali said.
(Reporting by Josh Smith; Editing by Raissa Kasolowsky)
