KDDI reported on November 6 that 12,233,087 email service records held by the internet service providers it supplies were leaked after its mail system was illegally accessed. The company announced the breach on June 23.
President Koji Matsuda apologized for the leak at an earnings briefing the same day, and opened the briefing with a second apology over a grassland fire in Mongolia linked to the activities of Mobicom Corporation, a KDDI subsidiary and Mongolian telecom operator.
"Despite how far technology has advanced, we kept operating an old system and leaked more than 10 million email addresses," Matsuda said. "We are working on cybersecurity measures so we can learn from this experience." He added: "We are sorry for the concern we have caused."
Two changes to how KDDI handles risk
Matsuda said KDDI will no longer hesitate to stop a service when a vulnerability is found and the situation requires it. Staff want to keep services running for customers, he said, but the company will now weigh stopping a service and responding against that wish, changing its criteria from before.
The second measure is a system to detect an intrusion early and limit the damage if one happens. "What I thought at the time was, why didn't we notice when so much information was taken?" Matsuda said. The leak convinced him that a delay in detection widens the damage, he said.
Both measures rest on threat intelligence — the observation and analysis of cyber threats — with KDDI working through prevention, detection and recovery.
Fire in Mongolia
Matsuda said the fire broke out on October 8 in the Nomgon nature reserve in Mongolia. "We sincerely apologize for the great worry and trouble we have caused the Mongolian government, the people of Mongolia, and everyone who has supported friendship and ties between our two countries over many years," he said. He thanked those who fought the fire and everyone in Japan and abroad working on the response.
Quarterly results
KDDI's consolidated revenue for the second quarter of the fiscal year ending March 2027 rose 4.7% from a year earlier to 3.0528 trillion yen, and operating profit rose 13.9% to 633.1 billion yen. Every segment posted higher revenue and profit.
Telecom core, which covers mobile communications, saw revenue rise 3.1% to 2.2010 trillion yen on a lower short-term cancellation rate within one year and more contracts on higher-tier plans. Personal growth, which includes financial services and the au Denki energy business, rose 8.3% to 605.3 billion yen. Business growth, which includes data centers and AI-related operations, rose 10.2% to 330.9 billion yen.