AhnLab reports cyberattacks on 13 companies

A total of 16 Web sites of 13 Korean companies, including the JoongAng Ilbo, came under a distributed denial of service (DDoS) attack for a day stretching to early yesterday, according to an AhnLab report.

No major damage was caused by the attack, the Korea Internet and Security Agency (KISA) said.

AhnLab, the country’s leading security software company, was among the targets of the DDoS attack. It said malicious viruses used in a small-scale attack in July apparently were used in the latest attack. Portal sites such as Daum, Nate and MSN, as well as the online homes of game software developers Nexon and Hangame were also attacked this time, AhnLab said.

The DDos attack is a common form of cyberattack in Korea. The attacks involve viruses that turn personal computers into “zombie PCs” and control them remotely without the knowledge of owners.

More than 10,000 computers were infected with viruses used in the latest attack, AhnLab said.

“Currently, all the malicious codes have been detected by all available vaccine programs in Korea, and we are treating it,” said an official of KISA. “The affected Web sites are functioning normally.”

The official urged personal computer users in Korea to update their security programs.

BY MOON GWANG-LIP, KO RAN [joe@joongang.co.kr]