"North Korea has attempted cyber attacks previously to spark public anxiety and hostility against the government," the Yonhap news agency reported, citing the Ministry of Science, ICT, and Future Planning.
Earlier in the month, the South Korean Defense Ministry announced it planned to create cyberdefense against online attacks from North Korea.
South and North Korea are still legally at war, as no peace treaty between them was signed after the Korean War of 1950-1953.
Long-standing tensions between the two Koreas flared up again in late August when cross-border artillery fire erupted along the Demilitarized Zone, prompting Pyongyang to declare what it described as a "semi-state of war." The two countries eventually defused the tensions during a series of talks.
Relations between the two countries further deteriorated when Pyongyang claimed it had carried out a hydrogen bomb test earlier this month.