ADVANTEST , the Japanese chip testing equipment maker, has disclosed that personal data was exfiltrated in the ransomware incident first disclosed in February 2026. The company now says hackers stole a range of personally identifiable information from its systems, including names, dates of birth, contact details, Social Security numbers, passport and driver’s licence numbers, and medical and financial information.
At the time of the breach notification, Advantest was still confirming whether any data had been exfiltrated, but the new filing confirms that personal data were indeed taken.
In terms of impact, Advantest has not disclosed the total number of affected individuals. Its filing with the California Attorney General indicates more than 500 California residents were affected. Notifications to attorneys general in Massachusetts and Vermont list 14 and 8 affected residents respectively.
The company emphasises that there is no evidence to suggest that the PII has been publicly disclosed or misused, though it warns that the incident may have placed individuals at increased risk of identity theft or fraud.
There is no indication that a specific ransomware group has claimed responsibility for Advantest’s attack. The article notes that, despite the breach, Advantest has not provided further details on the attackers or the precise method used for data exfiltration. The disclosures underscore the ongoing risks to organisations that suffer ransomware intrusions and the importance of timely breach notification and risk communication to affected individuals.