One of Japan's most important defence contractors has been hit by hackers.
The Yomiuri newspaper said that Mitsubishi Heavy Industries' computer network was hacked.
Yomiuri claims that the hackers seem to have found what they wanted. Data from the company's computer system was seen stolen in a cyber attack.
Mitsubishi Heavy confirmed the cyber attack, but said the firm is still investigating the case. It was not sure if data had been stolen.
It looks like more than 80 virus-infected computers were found at MHI's headquarters in Tokyo, and manufacturing and research and development sites, including Kobe Shipyard & Machinery Works, Nagasaki Shipyard & Machinery Works and Nagoya Guidance & Propulsion System Works.
Kobe is the one-stop shop for those who want to buy a submarine or components for nuclear power stations.
Nagasaki Shipyard makes escort ships, which are always useful if your ship needs an escort in foreign parts. The Nagoya plant makes guided missiles and rocket engines.
So far, no one has pointed the finger at China for the hack. It is a bit out of the league of North Korea and too well organised to be anything other than a foreign power.