Denso, a top Toyota supplier, was targeted by a ransomeware attack last week, the partsmaker said.
The Japanese supplier said it had detected unauthorized access using ransomware at Denso Automotive Deutschland GmbH, a group company that handles sales and engineering in Germany, on Thursday local time.
Denso "promptly responded," spokeswoman Izumi Saito said on Sunday.
At the moment Denso’s operations are not being impacted by the attack, she said.
Pandora, the group that allegedly accessed Denso's systems, threatened to disclose the supplier's trade secrets including email, invoices and part diagrams on a website on the dark web, national broadcaster NHK reported, citing Japanese cyber security firm Mitsui Bussan Secure Directions.
The group said it had more than 157,000 purchase orders, emails and sketches, or 1.4 terabytes worth of data, NHK said.