North Korea has reportedly created a team of 3,000 online trolls to demoralise their enemies and raise the profile of leader Kim Jong-Un.
Using identities stolen from South Korea, the hackers post comments on the country's Internet bulletin boards and forums.
The cyber agents also spread propaganda by hacking websites and linking them back to pro-North Korean sites, the Daily Express reports.
In June, hackers shut down 69 websites, including those of South Korean government offices and news services.
The hackers also stole personal data from 2.5 million members of the ruling party, 300,000 military personnel and 200,000 users of the presidential website, the report added.
