SEOUL, July 8 (Xinhua) -- Distributed denial-of-service (DDoS) attacks that struck a number of South Korean websites late Wednesday, including the presidential office Cheong Wa Dae's, have been confirmed to originate from some of the zombie computers infected in massive attacks a year ago, police said Thursday.
"We found yesterday's DDoS attacks traced to zombie computers that were used in last year's attacks and left untreated, which became active at the same hour and same day after lying dormant for a year," the Cyber Terror Response Center of the National Police Agency said Thursday.
Zombie computers are computers that have been secretly compromised by hacking tools which allow a third party to be in control of them.
These computers are assumed to be programmed to resume the attacks on 25 designated websites in South Korea and the United States on July 7 every year, the center said.
The police said that a mere 462 zombie computers were used in the latest attacks, compared with 270,000 last year.
