Information society which came due to advance of Information Technology improved the social and economical productivity as well as the quality of national life. But behind the right function the adverse effect as cyber terror is serious and become a big issue. Recently, hackings on a big scale occur frequently. The personal information stored in Internet company is leaked and customers are badly damaged by paralysis of banking system. Also hacking attacks by North Korea occur frequently. It causes confusion in our society and a threat to national security. In this paper, the trend of domestic cyber terror is observed and the countermeasure against cyber terror is proposed.