The personal information of almost 1,000 North Korean defectors has been stolen after hackers targeted an agency which helped them resettle in South Korea.
Officials said Friday that a computer belonging to the Gyeongbuk Hana Center was "infected with malicious code," enabling hackers to access the information -- including names, birth dates, and addresses -- of 997 defectors.
The center is operated by the Hana Foundation, a non-profit body set up in 2010 by the Unification Ministry to provide "protection and settlement support for North Korean defectors."
About 30,000 defectors are registered as living in South Korea. In the past, prominent defectors have been targeted by the North Korean authorities and families left behind in the North have faced punishment.
"Currently no harm or damage has been observed due to the leak," a Unification Ministry spokesman told CNN. "We have been contacting each defector (to brief them)."
In a statement, the Hana Foundation said it offered "our sincere apology" to those affected.
"The PC had been immediately disconnected and secured," it added. "The personal information that had been leaked (which includes name and birth date) will be explained individually over phone or mail. We are operating a hotline to report issues and damages."
A North Korean defector surnamed Choi told CNN there was concern that someone working for the organization might have "purposefully leaked it."
"Once the personal information is leaked to North Korea, those people's families back home will be registered and fall under constant surveillance. They (affected defectors) are distraught," he said.
In a statement, the Unification Ministry said the hack had been detected during a check of the computers by a "related authority," which then ordered an on-site investigation.
On the compromised computer were files containing the personal information of defectors based in the eastern region of Gyeongbuk, which had been created by the Hana Foundation "to provide support for the defectors."
Those files were "leaked due to the hack," the statement said, adding new security protocols were being implemented from January 2019.
"We apologize for causing worry to many defectors with this incident," the Ministry said, adding it would try to strengthen protection of personal information.
While the Ministry did not name a suspect in the hacking attack, North Korea is known to have a well-established cyber army which has been blamed for numerous attacks around the world.
In October, cybersecurity firm FireEye accused the North Korean government of using a state-sponsored hacking group to steal more than $100 million in "particularly aggressive" attacks on global banks.
North Korean hackers were also blamed for a major attack on Sony Pictures in 2014.