NEW YORK (AP) — There has been a brief but widespread internet outage that took major websites down. The websites of Airbnb, AT&T, Costco and Delta Air Lines on Thursday showed error messages around midday Eastern time. They seemed to be operating normally, however, by 12:45 p.m. Akamai, a major behind-the-scenes internet network company, says the disruption lasted about an hour and that it was due to a software update in the system that directs browsers to websites. It said there was no cyberattack. It is reviewing how it updates software to try to prevent outages in the future.