Kobe Steel Ltd. and satellite data provider Pasco Corp. have come under cyberattacks in the latest in a series of confirmed cases targeting defense-related companies in Japan, the Defense Ministry has said.
No leakage of classified information has been confirmed from either of the two companies, the ministry said Thursday.
Kobe Steel and Pasco both found that some of their intracompany network terminals were infected with a computer virus, thought to have been introduced through unauthorized external access to the systems in August 2016 and May 2018, respectively, according to the ministry.
Kobe Steel said a total of 250 files — including information on the ministry, as well as personal data — might have been leaked. The company has taken measures to bolster its cybersecurity.
A Pasco official quoted a third party as saying the attacker may have links to China.
Kobe Steel has been a supplier of submarine parts for the Self-Defense Forces, while Pasco has provided the SDF with satellite data.
News of the hacking comes after Mitsubishi Electric Corp. and NEC Corp., both of which play a significant role in Japan’s defense and infrastructure industries, acknowledged last month that they had come under major cyberattacks over the past few years. No highly classified defense secrets are believed to have been leaked in those attacks.
Defense Minister Taro Kono said last week that two other defense contractors had come under cyberattacks aside from Mitsubishi Electric and NEC, but did not identify them.
Mitsubishi Electric has said it identified suspicious activity on its server last June, and that among the potentially leaked information were email exchanges with the Defense Ministry, as well as documents related to projects with private companies including utilities, railway operators, communications companies and automakers.
NEC said information such as technical proposals it had made to the SDF on submarine sonar might have been leaked when 27,445 files were accessed without authorization over several years through 2018, according to sources close to the matter.
The sources said Chinese cybercrime groups were suspected of having gained unauthorized access to systems owned by the two Japanese electric giants.