By Hyunjoo Jin and Joyce Lee
SEOUL, Dec 1 (Reuters) - South Korean police said on Monday that they are tracing IP addresses and looking into possible tech vulnerabilities at Coupang CPNG.N after the e-commerce giant suffered the country's worst data breach in over a decade.
The personal data of more than 33 million customers was leaked in a breach believed to have started on June 24 through overseas servers, though the company did not learn of the problem until November 18.
South Korea's Science Minister Bae Kyung-hoon said on Sunday that the perpetrator had "abused authentication vulnerabilities" in Coupang's servers, adding that authorities would be investigating whether the company violated rules regarding the protection of personal information.
Coupang, which is backed by Japan's SoftBank Group 9984.T, has said the breach exposed customers' names, email addresses, phone numbers, shipping addresses and certain order histories, but not payment details or login credentials.
Broadcaster JTBC has reported that after conducting an internal investigation, Coupang suspects that a Chinese former employee, who was responsible for authentication tasks, was a key figure in the data breach.
A former employee used their authentication key that was still active after the termination of the person's contract to get access to customer information, lawmaker Choi Min-hee said in a statement on Monday.
Police and Coupang declined to comment on possible suspects.
As of Monday afternoon, internet postings showed that more than 10,000 people planned to join a possible class action lawsuit against Coupang. Lawyer Ha Hee-bong said the potential class action could seek compensation of more than 100,000 won ($68) per person.
Coupang, founded by Korean-American Harvard graduate Bom Kim in 2010, is the country's most popular e-commerce platform. It has overtaken family-owned conglomerates like Shinsegae in South Korean e-commerce and is also expanding into food delivery, streaming and fintech.
($1 = 1,471.0800 won)
(Reporting by Hyunjoo Jin and Joyce Lee; Editing by Edwina Gibbs)
((hyunjoo.jin@thomsonreuters.com; 82-2-3704-5685; Reuters Messaging: hyunjoo.jin.thomsonreuters.com@reuters.net))