U.S. based Internet security company McAfee says North Korea or its sympathizers was behind this year’s cyber attacks on the South Korean government and financial institutions.

The Associated Press quoted a McAfee report as saying it is likely the large-scale attacks that paralyzed U.S. government Web sites in 2009 are related to those that occurred in Korea this year.

The report concluded that the distributed denial of service, or DDoS, attacks on more than 20 sites in South Korea were a test to see how quickly the government would respond and reverse the damage.

The Korean National Police Agency’s Cyber Terror Response Center said in March that North Korea was behind the DDoS attacks on the presidential office, the National Intelligence Service, other government institutions and financial institutions.