The Democratic People's Republic of Korea (DPRK) was behind the March 20 cyber attack against South Korea that paralyzed computer networks at banks and broadcasters, Yonhap News Agency reported on Wednesday.

According to a government official cited by Yonhap, the probe into access records and the malicious codes showed that the DPRK' s reconnaissance general bureau masterminded hacking attacks that crippled networks at three domestic banks, including Nonghyup, Shinhan and Jeju, and three broadcasters, including KBS, MBC and YTN.

The South Korean government planned to announce its formal probe results later in the day.