Auto parts maker Denso targeted in ransomware cyberattack

Hackers targeted major auto parts manufacturer Denso Corp. in a ransomware cyberattack in late December, but company officials said the incident has not affected business operations.

A hacker group calling itself Rook issued a statement on its website claiming responsibility for the cyberattack and said it had stolen 1.1 terabytes of data from Denso.

According to Nobuo Miwa, president of the internet security company S&J Corp., the posting by Rook about Denso was suddenly deleted on Jan. 4.

Miwa explained that Rook likely had ties to another hacking group that stopped operating last year and may have been trying to cover its tracks.

“These groups frequently change their names while conducting criminal behavior to avoid detection,” Miwa said.

Denso is Japan’s largest auto parts manufacturer with annual sales of 5 trillion yen ($44 billion). It belongs to the corporate group led by Toyota Motor Corp.

According to Denso officials, the company was aware of the cyberattack even before Rook claimed responsibility.

Company officials handling internet security investigated and determined their domestic computer systems had not been breached. They also determined that overseas business operations had not been affected.

But they learned that a North American facility had been hit by the ransomware virus. About 20 computers used in a plant in Mexico and connected to an old network were breached. All data and important information indispensable for business operations at that plant had already been transferred to a new computer network.

The Mexican plant was able to resume operations as planned on Jan. 3. It remains possible that the personal information of the workers at the Mexican plant was among the data stolen.

Denso officials said they could not comment on whether it paid the ransom or if it negotiated with Rook because local investigative authorities are currently looking into the case.

There have been frequent instances of ransomware attacks in recent years.

In 2020, Honda Motor Co. was forced to suspend operations at nine plants overseas after its system was hit with ransomware.

In November that year, the video game development giant…