People who apparently took part in this weekend’s denial of service attacks against several major North Korean websites have promised there’s more to come.

The attacks hit sites including KCNA, Voice of Korea, the Committee for Cultural Relations with Foreign Nations and Air Koryo. They also targeted the Korean Friendship Association’s site although I wasn’t able to verify whether it went down.

A denial of service attack involves flooding a web server with so much traffic that it becomes overloaded and cannot respond to legitimate requests for pages. It’s different from the site being hacked, although the end result is similar in that users cannot access the pages.

As of lunchtime Monday Korean time, most of the sites are back online although the KCNA.kp remains impossible to access.

Many of those apparently involved in the attacks were posting on Twitter using the #OpNorthKorea hashtag. On Sunday, some of those messages indicted the coordinated attacks were winding down — for now.

130401-twitter-01

 

April 19 corresponds to South Korea’s “April Revolution” of 1960 when students took to the streets and ultimately led then-President Syngman Rhee to resign. June 25 was the day in 1950 when the Korean War began.

The selection of those dates could be a hint that some of the attackers have South Korean roots.

The messages also included a new Twitter hashtag: #OpKoreanWar.

130401-twitter-02

 

So, what did the attacks achieve? Inside North Korea, probably nothing more than an annoyance to the people running the websites. Ordinary North Koreans don’t have access to the Internet so those websites are purely intended for a foreign audience.

Probably those most affected were North Korea watchers and journalists who wanted to check the latest messages from the North Korean government, the majority of which reach most through the KCNA wire service.

The attacks were the latest in a string of Internet-related incidents in North and South Korea.

Although this round of attacks appears to have been prompted by North Korea’s declaration that “north-south relations will be put at the state of war and all the issues arousing between the north and the south will be dealt with according to the wartime regulations.”

The denial of service attacks are a digital version of something North Korean has been doing for years. Radio broadcasts from outside the country are regularly jammed by the country to prevent citizens from listening. The jamming involves broadcasting a strong signal on the same frequency as the radio station so its signal cannot be heard.

UPDATE: An earlier version of this story incorrectly stated June 15 was the birthdate of Kim Il Sung. That was incorrect. The correct date is April 15.