The CIA's website, which crashed Thursday afternoon, was revived shortly before 11 a.m. Friday morning. The spy agency declined to discuss what might have caused the blackout, but Office of Management and Budget officials referred all questions to civilian cybersecurity authorities at the Homeland Security Department, which suggests the event was an attack.
A CIA spokeswoman said in an e-mail: "Websites sometimes experience technical difficulties. The agency is making every effort to restore CIA.gov as soon as possible."
Soon after she wrote, the site was back up and offering "the second installment in the lighthearted K-9 Cam series" on how to become a bomb-sniffing CIA dog, and posing this intriguing question: "What country has three megacites with populations of greater than 15 million? (No, it's not China.)"
Later in the day, CIA spokeswoman Marie Harf said the agency was still analyzing the "technical problems," which also included an e-mail outage that took down employees' unclassified messages.
The CIA overhauled its website in February "to make information about the agency available to more people more easily," Director Leon Panetta said at the time.
The new site includes links to a CIA YouTube channel -- videos of Panetta giving a speech, Chessie the bomb-sniffing dog -- and a Flickr photo site showing shots of Panetta giving a speech and pictures of a U-2 spy plane. It also offers ready access to the CIA "World Factbook."
More change is coming. "CIA.gov is developing a truncated, text-based version" of its website to be more easily accessed by people with smart phones and other handheld wireless devices, the agency said.
Aliya Sternstein contributed to this report.