Advantest confirms data theft after ransomware attack

Advantest Corporation said a threat actor entered its network on 15 February and accessed some systems. The company had earlier said hackers had reached parts of the network and deployed ransomware, but it could not then tell whether customer or employee data had been affected.

In a breach notice dated 6 October 2026, Advantest said data had been taken from its servers. The notice said the material included personal information belonging to the recipient.

The types of information listed in the notice were contact details, dates of birth, Social Security numbers, national ID numbers, driver’s licence and passport numbers, medical information, financial information and other ID numbers. The report said it was not clear whether the people affected were customers, employees, partners or a mix of those groups.

Advantest said it did not know of any leak or misuse of the data. It offered 18 months of identity theft, credit and web monitoring through Kroll, and gave recipients until 4 January 2027 to activate the service.

The report also said it had found no public claims from ransomware groups targeting Advantest at the time of writing. It advised affected people to watch their accounts and statements, and to be cautious about phishing messages and unexpected requests for money or sensitive information.