Japanese pharmaceutical firm Shionogi & Co. said Thursday that its Taiwanese subsidiary was hit by a cyberattack earlier this month leading to a data breach, although no information regarding the novel coronavirus vaccine it is currently developing was leaked.

According to the company, import licenses for medical equipment and employee residency permits were released on the "dark web" after a computer in its Taipei sales office was infected with a virus in mid-October.

The attacker has threatened to release more information unless a ransom is paid.

Shionogi said there have been no indications of unauthorized access among its computers at laboratories and offices within Japan.

While clinical trials are carried out in Taiwan, the local subsidiary does not deal with matters involving cutting-edge technology or personal information, it said.

Japan has not been immune to the spate of cyberattacks targeting research institutions developing coronavirus vaccines worldwide.

A U.S. information security firm said Monday some Japanese research institutions involved in coronavirus vaccine projects had experienced attempted cyberattacks since April. Based on the techniques employed, they suspect a Chinese hacker group is behind the attacks.

Attacks using ransomware, a type of malware that threatens to publish the victim's data unless money is paid, has been on the rise in Japan.

Nobuo Miwa, president of information security firm S&J Corp. in Tokyo, warned that "Information about a vaccine is appealing for criminals after money."