SEOUL, South Korea -- South Korea blamed North Korea on Tuesday for a wave of cyberattacks that paralyzed 69 Web sites last month, including those belonging to the presidential office and local media companies.
The South Korean Science Ministry said it reached its conclusion after analyzing the damaged servers and personal computers, malicious codes, Internet Protocol addresses and other data used in the attacks, which took place on June 25, the 63rd anniversary of the outbreak of the 1950-53 Korean War.
A government panel of investigators also found similarities between the codes and other hacking methods used in the June disruptions and the cyberattacks that shut down tens of thousands of computers at South Korean broadcasters and banks in March. The South had earlier blamed the North for the March attacks.
In the June attacks, people who said they were part of a global network of hackers called Anonymous claimed responsibility on Twitter. On Tuesday, the South Korean ministry said the North probably used the claims to create confusion about the source of the attacks.
On June 25, major Web sites in North Korea were also shut down in what South Korean media called cyberattacks. The rival Korean governments have accused each other of hacking attacks in recent years, although they officially deny their own involvement.
The hacking attacks in June were the latest in a series of "cyberterrorism" cases that South Korea has cited as evidence that the North was running an army of Internet warriors to disrupt the South, one of the world's most wired countries. South Korean officials have said that countering with their own hacking operations would have only limited effect on the North, since most of its society and government has been kept from Internet access.
"These were meticulously planned attacks that had been prepared at least for several months to find the weak spots of their targets," said Park Jae-moon, a senior ministry official, during a media briefing. He said the hackers operated through file-sharing Web sites in South Korea.
Investigators said that a lot of personal data was lost from the stricken Web sites, although they managed to recover them from the damaged hard drives.
Earlier this month, the cybersecurity firm McAfee Labs, based in Santa Clara, Calif., said that its analysis of the March attacks in South Korea showed that "the incident was more than cybervandalism."
"The attacks on South Korean targets were actually the conclusion of a covert espionage campaign," it said. While reporting that the attacks were trying to steal South Korean and American military data, McAfee did not blame North Korea by name. It also added that the "overall tactics were not that sophisticated in comparison to what we have seen before."
This article originally appeared in The New York Times.