Citing Japanese press reports, anti-virus services provider Sophos reported that the infected computer of an employee from Mitsubishi Electric is believed to have leaked about 40MB of confidential reports.
Officials from the Japanese firm said the leak occurred when the employee used his virus-infected personal computer for company business. The virus enabled Winny users across Japan to access the sensitive information, which included photographs of the insides of the nuclear power plants, and the names and addresses of inspecting engineers. Winny, or WinNY, is a Japanese peer-to-peer program.
"If you allow your employees to put sensitive company data onto their own home computers, you are running the risk that they will not be as well defended as the PCs within your organization," Graham Cluley, senior technology consultant at Sophos, said in a statement.
Mitsubishi Electric representatives said it does not believe the information leaked was directly related to radioactive substances.