Japan's largest defense contractor backpedaled yesterday, saying it's possible some secrets had been stolen by hackers who broke into the company's network and planted malware in August.
The acknowledgement came several weeks after Mitsubishi Heavy Industries, confirming that scores of its servers and PCs had been infected, denied any information had been pilfered.
Previously, a U.S.-based Mitsubishi Heavy spokesman had said that although attackers had uncovered company IP (Internet Protocol) addresses, the attack "was caught at an early stage."
But yesterday the company changed its tune, saying that more investigation had revealed a possible loss of information.
"The company recently confirmed unintended transferring of some information on the company's products and technologies between servers within the company," said Mitsubishi Heavy in a statement. "Based on the finding, the company investigated the incident further and recognized the possibility of some data leakage from the server in question."
The company declined to confirm that any diversion of data related to defense or nuclear technologies took place.
Mitsubishi Heavy's admission came on the same day that the Japanese newspaper Asahi Shimbun cited unnamed sources who said data on company-built fighter jets, helicopters and nuclear power plants had apparently been stolen during the attack.
Last month, Mitsubishi Heavy said that among the 83 compromised servers and PCs were ones at its Kobe shipyards, where the company builds diesel-electric submarines and components for nuclear power plants; at the company's Nagasaki shipyards; and at its Nagoya plant, which designs and manufactures missile guidance systems.
The firm's corporate headquarters was also targeted by attackers.
Mitsubishi Heavy said it was continuing to investigate and would cooperate with Japanese authorities, who have been involved since late September when the company filed a complaint with the Tokyo Metropolitan Police Department, said Asahi Shimbun.
The August attack was the first against a major Japanese defense contractor, but followed others earlier this year aimed at U.S. companies, including Lockheed Martin, which manufactures the F-22 Raptor and F-35 Lightning II fighter aircraft. The Lockheed attack was carried out using information stolen earlier from RSA Security, the branch of EMC that produces the SecurID two-factor authentication token used by thousands of contractors and corporations to secure their networks.
Defense News ranked Mitsubishi Heavy as the world's 26th-largest defense contractor last year.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed . His e-mail address is firstname.lastname@example.org.