US officials are investigating multiple attacks that caused widespread online disruption on both sides of the Atlantic on Friday.The incident took offline some of the most popular sites on the web, including Netflix, Twitter, Spotify, Reddit, CNN, PayPal, Pinterest and Fox News – as well as newspapers including the Guardian, the New York Times and the Wall Street Journal. The attacks seemed to have been focused on Dyn, one of the companies that run the internet’s domain name system (DNS). No one has yet claimed responsibility for the attacks, according to researchers. The attacks underline a serious vulnerability in the way the internet functions. David Gibson, of commercial security software firm Varonis.