Japanese chip testing giant Advantest is informing individuals that hackers stole personal information in the ransomware attack disclosed in February 2026.
Advantest, which makes automatic test equipment for chipmakers such as Intel and Samsung, said in February that hackers had breached its network and deployed ransomware.
At the time, it was still working to determine whether any sensitive information had been exfiltrated.
In data breach notifications sent out now, the company said the attackers stole personally identifiable information, including names, dates of birth, contact information, SSNs, passport and driver’s license numbers, and medical and financial information.
“We have no information suggesting that your PII has been disclosed publicly or otherwise misused,” Advantest said. “However, this incident may have placed you at increased risk of identity theft or fraud.”
The company has not disclosed how many individuals were impacted by the data breach, but its filing with the California Attorney General’s Office indicates that more than 500 California residents are affected.
Notifications submitted to attorneys general in Massachusetts and Vermont list 14 and 8 affected residents, respectively.
No known ransomware group appears to have taken credit for an attack on Advantest.
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