Yesterday, a U.S.-based spokesman for Mitsubishi confirmed that the company had uncovered a that had planted malware on 45 servers and an additional 38 individual PCs in several locations around Japan.

Servers at Mitsubishi's 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, were among those compromised, the spokesman said.

The attacks were first detected in mid-August, said Mitsubishi, but the company did not go public until Japanese media revealed the intrusion. According to Japanese reports, the government was not informed by Mitsubishi of the attack before this weekend.

The spokesman declined to comment on the origin of the attacks.

Separately, however, Japan's National Police Agency (NPA) today circulated a of attacks against government websites based on chatter in Chinese forums.