TOKYO, Oct. 17 (UPI) -- Japanese officials say they believe recent cyberattacks on two large corporations were the work of the same hacker attempting to steal Japanese defense secrets.
Police said a computer virus found in the attacks on Kawasaki Heavy Industries and Mitsubishi Heavy Industries forced infected personal computers to access a Web site in the United States and exchange data, The Yomiuri Shimbun reported Monday.
Experts said the hacker was probably using the U.S. site as a so-called springboard, a computer or server used unbeknownst to its operators as relay points by hackers to hide their originating port, which can be anywhere in the world.
Police said they have asked U.S. authorities to help monitor traffic on the U.S. site.
Experts said it was unusual for the same springboard to be used in separate attacks.
"Usually, hackers use different springboards for individual attacks, so the same server is rarely used by two or more criminal groups," said Norihiko Maeda, a researcher at Kaspersky Lab Japan.
"[However, because the police investigation found that] the same attacker likely targeted the two companies, it's become clearer that the attacker aimed to steal Japanese defense secrets," he said. "Authorities must quickly investigate communication records and other data from the springboards."