SK Telecom's (KRX:017670) attributable net income in the second quarter surged 425% year over year on the back of easing costs from a 2025 cybersecurity breach and strong growth in its artificial intelligence data center businesses.

Net income more than quintupled to 470.6 billion won from 89.6 billion won a year earlier, according to its earnings statement published Wednesday.

Basic earnings per share climbed to 2,186 won from 398 won a year earlier.

Operating income surged 67% on year to 566 billion won, which SK Telecom attributed to "profitability‑focused management" and positive effects from last year's USIM replacement costs.

The company offered free USIM card replacements from April 2025 to all subscribers to prevent potential identity theft or financial fraud resulting from a data breach caused by an unidentified server cyberattack. The company was fined a record 134 billion won in connection with the breach.

Meanwhile, revenue in the second quarter edged up 0.47% to 4.359 trillion won from 4.339 trillion won. The almost-flat movement was due to a 1.9% decline in mobile service revenue amid a drop in subscribers. This was offset by 3.6% revenue growth in SK Telecom's Broadband unit on strong data center demand.

The company's AI data center business continued to grow, with revenue climbing 92.5% year over year to 136.2 billion won on higher utilization and increased revenue contribution from its submarine cable operations.

SK Telecom launched a new unit called SK Hyper last month to operate its data center business.

"Going forward, we will make every effort to play a leading role in enabling Korea to emerge as an AI infrastructure hub in Asia," said SK Telecom CFO Park Jong-seok.

The company declared a quarterly dividend of 830 won per share, unchanged from the first quarter.