Seoul: A massive data breach attack against e-commerce giant Coupang Inc. that has affected over 30 million customers' data lasted from June to November and involved the exploitation of the company's electronic signature key, according to officials Tuesday.

According to Yonhap News Agency, Second Vice Minister Ryu Je-myung revealed during a parliamentary session that the breach was identified after a thorough review of log data from July last year to November this year. "We have confirmed that private data from more than 30 million accounts was leaked," Ryu stated. The attack reportedly spanned from June 24 to November 8, utilizing Coupang's electronic signature key, which is essential for accessing the company's servers.

Ryu emphasized the necessity of a police investigation to uncover the perpetrator behind the attack. This follows reports of an alleged former Coupang employee who contacted the company via email, claiming responsibility for the theft of the personal information of over 30 million individuals.

Last week, the U.S.-listed e-commerce giant announced that the personal information of 33.7 million customers had been compromised. This breach involved sensitive details, including names, phone numbers, email addresses, and delivery information for nearly all Coupang members.

Coupang, known for its overnight delivery of fresh food and daily necessities, is a leading shopping platform in South Korea, boasting 34 million monthly active users as of November, marking a 0.68 percent increase from the previous month.

The incident has intensified public concern regarding South Korea's data protection capabilities, especially in light of a series of significant data leak cases this year involving major corporations like telecom giants SK Telecom Co. and KT Corp., as well as the credit card firm Lotte Card Co.