“The FBI broke the news to executives at DuPont Co. late last year that hackers had cracked the company’s computer networks for the second time in 12 months, according to a confidential Dec. 9, 2010, e-mail discussing the investigation.
About a year earlier, DuPont had been hit by the same China- based hackers who struck Google Inc. (GOOG) and unlike Google, DuPont kept the intrusion secret, internal e-mails from cyber-security firm HBGary Inc. show. As DuPont probed the incidents, executives concluded they were the target of a campaign of industrial spying, the e-mails show. “
Source: Hacking of DuPont, J&J, GE Were Google-Type Attacks That Weren’t Disclosed – Bloomberg