Important personal data like names, birthdates, credit card numbers, and employment information for over 3.1 million customers were stolen from Toyota Japan’s computers in what experts traced to a cyberattack launched by a Vietnam-based hacking group.

Sean Lyngaas tells more about the Toyota data breach in this report from CyberScoop:

The breach affected Toyota Tokyo Sales Holding Inc. and its affiliated enterprises, and possibly three other independent dealers in Japan, according to Toyota Motor Corp.’s statement, which described “unauthorized access” to the company’s network.

“We take this situation seriously, and will thoroughly implement information security measures at dealers and the entire Toyota Group,” the statement said.

It was the second cybersecurity incident affecting Toyota in as many months. In February, Toyota’s Australia branch announced it had been “the victim of an attempted cyberattack.”

The company’s security woes come in the wake of reports that a Vietnamese hacking group, APT32, had last month launched a spearphishing campaign against multinational car companies. The Southeast Asian country is trying to develop its domestic car industry, and data stolen by APT32 could help with that.