SEOUL, Jan. 15-- A large amount of emails impersonating the South Korean presidential office and the foreign ministry to poll opinions about the Democratic People's Republic of Korea (DPRK)'s fourth nuclear test had been sent to government officials, local media reported Friday citing police and the intelligence agency.

The impersonated emails had been sent to those in Seoul government offices since Pyongyang claimed on Jan. 6 that it successfully tested a hydrogen bomb.

The emails were titled as the presidential security office's opinion poll on a way of response to the DPRK's fourth nuclear test or a written request for advice on the DPRK's fourth nuclear test.

South Korea's conservative daily newspaper Chosun Ilbo reported that a malicious code, believed to be developed in the DPRK, was contained in the emails. Opening the mail or clicking on the attached file exposes computers to hacking attacks, the newspaper said citing the police.

The South Korean police and the intelligence agency have launched an investigation into the impersonated emails, opening a possibility for the DPRK's cyber attacks.