FBI investigating major cyber attack on popular websites

The FBI has said it is investigating a wave of apparently coordinated cyber attacks which disrupted access to dozens of major websites including PayPal, Amazon, AirBnB, Twitter and Spotify on Friday.

Internet users were hit by outages and left unable to make online payments as a result of a series of DDoS (distributed denial-of-service) attacks on the internet server company Dyn.

Such attacks overwhelm the servers managing internet traffic by pounding them with so many requests for information that they shut down and cannot function.

The outages had begun in the Eastern United States, and then spreadto other parts of the country and Western Europe including the UK.

Dyn said it had resolved one morning attack, which disrupted operations for about two hours, but disclosed a second a few hours later that was causing further disruptions.

PayPal said that the outage prevented some customers in "certain regions" from making payments. It apologized to customers for the inconvenience and said that its networks had not been hacked.

Among the other sites hit by the attacks were CNN, HBO Now, Mashable, the New York Times, People.com, the Wall Street Journal and Yelp, according to reports.

Dyn said it was still trying to determine how the attack led to the outage but that its first priority was restoring service.

The US-based company is a major domain name servers (DNS) manager, which acts as an essential middleman in loading websites.

Attacking a large DNS provider can create massive disruptions because such firms are responsible for forwarding large volumes of internet traffic.