"We believe there's a larger possibility that North Korea may launch cyber attacks on the South, and recently upgraded our Information Operation Condition (INFOCON)," the official said, without elaborating further.
INFOCON was apparently raised from Level 4 to Level 3. The five-tier threat level system has been used by the military to defend against a computer network attack.
It was earlier upgraded from Level 5 to Level 4 after North Korea's nuclear test last month. The news of the most recent upgrade comes a week after the North's launch of a long-range rocket.
The South Korean official said no hacking attempts have been identified against the Defense Ministry or the armed forces here, but added, "We believe North Korea is more likely to launch cyber attacks than before and we're keeping close tabs on potential signs."
YNA/MNA