In May 2021, the server of Seoul National University Hospital in Seoul was hacked. It was suspected that North Korea was behind the attack.

After a two-year investigation, Seoul police concluded Wednesday that the hacking was carried out by the North Korean hacking group known as "Kim Su-ki" and that it stole the personal information of over 830,000 people, including the medical records of 810,000 patients.

It is suspected that the hackers, using malware, looked into the medical records of patients, particularly of those who had undergone pathological tests.

Lee Seung-woon, the head of the National Police Agency's Cyber Terrorism Response Center, said the hackers appear to have specifically targeted the data, potentially in the hopes of obtaining the medical records of key personnel here.

The perpetrators set the password of the account created for the hacking to a phrase meaning "don't get hurt" in Korean.

In North Korea, the expression is widely taken as a warning not to touch or interfere. It appears to be a message left for South Korean investigators, the police officer said.