Cybersecurity authorities on Monday issued a joint warning against North Korean hackers trying to steal construction and machinery data in South Korea.The Korea Cybersecurity Intelligence Community, which includes the spy agency, prosecution, police and military, said North Korean hackers have targeted such information to help build plants and develop cities in the North.The authorities said they confirmed a sharp increase this year in the North's hacking attempts to steal such information.According to the authorities, the North's hacking groups used the "watering hole" method, which targets a large number of users by infecting websites they commonly visit, and malicious codes to steal information.Last month, South Korea's cybersecurity authority also issued a joint advisory with its U.S. and British counterparts against North Korea's cyber espionage campaign targeting classified information in defense, aerospace, nuclear and engineering sectors.Source: Yonhap News Agency