"The bad guys know which organizations have data worth stealing and are picking them out one by one," said Alex Shipp, senior technologist at MessageLabs, which has intercepted e-mail attacks coming from computers in China and Taiwan.
MessageLabs intercepted 716 corrupted e-mails last month aimed at 216 agencies and companies in the United States, USA Today reported Monday.
The attacks are working," said Alan Paller, of the SANS, a security think tank. "Penetrations are deep and broad."
Mark Miller, Microsoft's director of security response, advises workers to use "extreme caution" when opening Office files in e-mail, USA Today reported.
Notable deaths of 2014 [PHOTOS]
Larry Ellison to step down as CEO of Oracle