In April, South Korea’s telco giant SK Telecom (SKT) was hit by a cyberattack that led to the theft of personal data on approximately 23 million customers, equivalent to almost half of the country’s 52 million residents.
At a National Assembly hearing in Seoul on Thursday, SKT chief executive Young-sang Ryu said about 250,000 users have switched to a different telecom provider following the data breach. He said that expects this number to reach 2.5 million, more than tenfold the current amount, if the company waives cancellation fees.
The company could lose up to $5 billion (around ₩7 trillion) over the next three years if it decides not to charge cancellation fees for users who want to cancel their contract early, Ryu said at the hearing.
“SK Telecom considers this incident the most severe security breach in the company’s history and is putting forth our utmost effort to minimize any damage to our customers,” a spokesperson at SKT told TechCrunch in an emailed statement. “The number of customers affected and the entity responsible for the hacking is under investigation,” the spokesperson added.
A joint investigation involving both public and private entities is currently underway to identify the specific cause of the incident.
The Personal Information Protection Committee (PIPC) of South Korea announced on Thursday that 25 different types of personal information, including mobile phone numbers and unique identifiers (IMSI numbers), as well as USIM authentication keys and other USIM data, had been exfiltrated from its central database, known as its home subscriber server. The compromised data can put customers at greater risk of SIM swapping attacks and government surveillance.
After its official announcement of the incident on April 22, SKT has been offering SIM card protection and free SIM card replacements to prevent further damage to its customers.
“We detected possible information leakage regarding SIM on April 19,” the spokesperson at SKT told TechCrunch. “Following the identi …