1: Codes used in the attack were said to be similar in pattern to those used by the North Koreans , South Korean authorities said . 2: A report by the Korea Institute for Industrial Economics and Trade , a government-funded think tank , estimates that  Dark Seoul  caused about $ 820 million worth of damage . 3: December attack on banks in South Korea caused about $ 820 million worth of damage , a report says .
1: the attack 2: Dark Seoul 3: December attack on banks in South Korea