Mitsubishi's defence contract arm has been forced to admit that its systems were breached in an attack that it is claimed led to the leaking of military and nuclear secrets.
Mitsubishi Heavy Industries - the name given to the arm of the company which deals with defence contract work - admitted that it had been breached back in August, when unknown attackers breached 45 servers and 38 client systems across 10 of the company's Japanese facilities.
While the company admitted that Trojan applications that would allow for data to be copied from the servers was discovered, it held back on speculating on precisely what the attackers could have got away with.
Admitting the attack in September - a month after it occurred, a delay which saw the company receive a lambasting from Japan's Defence Ministry - led local media to investigate the matter themselves, and some frankly worrying information has come to light as a result.
The local news outfit Asahi Shimbun quotes unnamed sources close to the company as claiming that the attackers were able to retrieve sensitive information regarding fighter aircraft and attack helicopters that the company was involved with, along with design and safety plans for nuclear power plants.
That's not great news for Mitsubishi, which has previously worked on high-profile projects including the Patriot surface-to-air missile system in partnership with Raytheon and the F15J figher jet in partnership with Boeing.
Thus far, no group has come forward to claim responsibility for the attack.