Credit: REUTERS/Kevin Lamarque North Korea’s Internet was restored Tuesday local time, after an outage that lasted for 9 hours and 31 minutes, according to a company that monitors Internet performance.Dyn Research had earlier reported that the four networks in the country were down.The cause of the outage is not known, but led to speculation that the U.S. may have retaliated for North Korea’s alleged role in the hack of Sony Pictures in late November.The U.S. Federal Bureau of Investigation said Friday it held North Korea responsible for the attack, which came ahead of the planned release by Sony of a comedy movie about a plot to assassinate the country’s leader Kim Jong Un. President Barack Obama said soon after that at a news conference that the U.S. would respond proportionally to the attack “in a place and time and manner we choose.”“All four North Korean prefixes have been restored to service at 01:46 UTC, after a national outage of nine and a half hours. Traffic is routing through China Unicom, just as before,” Dyn said in an update. It also tweeted that North Korean-hosted websites had returned. The company had earlier reported that North Korea went off the Internet at 16:15 UTC after more than 24 hours of sustained weekend instability, but said such long outages were not without precedent in the country.“A long pattern of up-and-down connectivity, followed by a total outage, seems consistent with a fragile network under external attack,” wrote Jim Cowie, Dyn’s chief scientist in a blog post. “But it’s also consistent with more common causes, such as power problems.”North Korea is dependent on a single international provider, China Unicom.John Ribeiro covers outsourcing and general technology breaking news from India for The IDG News Service. Follow John on Twitter at @Johnribeiro. John’s e-mail address is john_ribeiro@idg.com Related content news Multibillion-dollar cybersecurity training market fails to fix the supply-demand imbalance Despite money pouring into programs around the world, training organizations have not managed to ensure employment for professionals, while entry-level professionals are finding it hard to land a job By Samira Sarraf Oct 02, 2023 6 mins CSO and CISO CSO and CISO CSO and CISO news Royal family’s website suffers Russia-linked cyberattack Pro-Russian hacker group KillNet took responsibility for the attack days after King Charles condemned the invasion of Ukraine. By Michael Hill Oct 02, 2023 2 mins DDoS Cyberattacks feature 10 things you should know about navigating the dark web A lot can be found in the shadows of the internet from sensitive stolen data to attack tools for sale, the dark web is a trove of risks for enterprises. Here are a few things to know and navigate safely. By Rosalyn Page Oct 02, 2023 13 mins Cybercrime Security news ShadowSyndicate Cybercrime gang has used 7 ransomware families over the past year Researchers from Group-IB believe it's likely the group is an independent affiliate working for multiple ransomware-as-a-service operations By Lucian Constantin Oct 02, 2023 4 mins Hacker Groups Ransomware Cybercrime Podcasts Videos Resources Events SUBSCRIBE TO OUR NEWSLETTER From our editors straight to your inbox Get started by entering your email address below. Please enter a valid email address Subscribe