A White House official said the attack targeted an unclassified network. He said the attack was identified and that the system was isolated to prevent spread. He said there was no indication that any data was removed.
Google, Microsoft and other companies are working together to combat email "phishing" scams. They've formed an organization to design a system to authenticate emails from legitimate senders and weed out scams.
Delta Airlines says it has been flooded with calls about mass email confirmations for round-trip flights between New York and San Francisco. The emails are so realistic, some of the included links are reportedly legit. But others are malicious.
The San Francisco-based online ticket broker, a subsidiary of eBay Inc., first learned of the scam early Thursday morning, and within a few hours was deluged with phone calls, said spokesman Glenn Lehrman.