On surface, tension between the two Koreas has subsided, and even North Korea suggested  a talk in recent days. Beneath the surface, however, intense cyber-attacks were leveled against each other. Sparked by one South Korean net user posting an insulting poem about the Kim family on the North Korean official website Uriminzokkiri, North Korea fired back with a DDOS attack.
Today, South Korean hackers have allegedly attacked the North Korean government's official twitter account @uriminzok, filling the timeline with harsh slurs about North Korea's Kim family, according to South Korea's citizen media Wiki Tree [ko] and other media. It is believed that net users from DC Inside Gallery, one of South Korea's most popular community sites, have pulled the trigger as a way of retaliating North Korea's DDOS attack on the site. Yesterday, North Korea halted the site for about 30 minutes after one user from the site posted a poem insulting the regime on the North Korean official website.
Wiki Tree added that yesterday late afternoon @uriminzok tweeted ‘South Korea should accept our suggestion’, resonating the regime's propaganda. But at around 8 o'clock this morning, four tweets lambasting the Kim family filled the timeline .
Below is a translation of some tweets:
300만 인민들이 굶어죽고 얼어죽었는데 초호화별장에서 처녀들과 난잡한 술파티를 벌이고 있는 김정일을 처단하자.[…]
“조선인민군대여! 인민군들을 먹일 돈으로 핵과 미싸일 개발에 14억 딸라를 랑비한 김정일 력도에게 총부리를 겨누자”
“DPRK army! Let's point our rifles at traitor Kim Jong-il who squandered about 1.4 billion dollars on developing nuclear weapons and missiles, instead of supporting the North Korean army.
It is also believed that the official website Urimnzokkiri site have been hacked and an illustration of the Kim family bowing to a Chinese emperor in subservience was posted on its main page. But it takes time to confirm the news, since almost every North Korean website is blocked in South Korea.
What sparked this series of attacks was a smart poem posted by the DC Inside Gallery user. Free North Korea Radio , a Seoul-based radio station run mostly by North Korean defectors, revealed on January 4 that a 12-line poem, which looked like a lavish praise of the Kim family at first glance but actually a direct insult to the North Korean regime, was posted on the North Korean government’s official site Uriminzokkri between December 20-21 last year. It was read by several hundred people.
The title of the post is believed to be ‘The first letters are the real one.’ When read from left to right which is the proper way of reading Korean, it is a typical North Korean poem lauding the Kim regime and showing hostility towards the US . But if you read only the first letter of each sentence, a hidden message emerges: ‘Kim Il-sung is a lunatic. Kim Jong-un is the son of a b**ch.’
This vertical reading is a popular way among young Koreans when delivering hidden messages.
The hacker/writer of the poem left his trail on DC Inside Gallery. This so-called ‘holy ground’ page[ko] showed  communications made between net users, with one suggesting ‘shall I rob the Uriminzokkiri site,’ and one replied, ‘when I tried the site with ‘the vertical tactic’, it worked.’