Daiichi Kosho’s October 8 notice warned that malware at contractor Nippon Columbia Group could have exposed about 8.724 million customer and employee records. It said one computer was isolated on October 2 after infection was detected on October 1–2; the contractor reported the incident on October 5.
The company said an actual external leak, misuse and effects on its own systems had not been confirmed. Possible affected fields include names, birth dates, email addresses and phone numbers; passwords were excluded.
An October 9 follow-up opened a dedicated enquiry line and said investigation continued. These are records, not a confirmed count of distinct victims or proven stolen files. Sources: Daiichi Kosho, October 8–9; BleepingComputer, October 11.