Popular Australian media, banking, insurance, retail and hotel websites have experienced outages and interruptions following cyberattacks in the US overnight, according to digital performance monitoring company Dynatrace.

The international attacks targeted Dyn, a company that helps people connect to websites, with a huge amount of traffic in an attempt to knock the service offline, according to Dyn's director of internet analysis, Doug Madory.

The Distributed Denial of Service (DDoS) attack came in three waves and left millions of users, mostly in the US and Europe, unable to access many popular websites including Twitter, Spotify and Netflix.

According to data by Dynatrace, interruptions were experienced by Australian websites including AAMI, ANZ, BankWest, Coles, The Daily Telegraph, Dan Murphy's, ebay, HBSC, The Herald Sun, NAB, 9News, The Age, Ticketmaster, The Australian, Woolworths, The Sydney Morning Herald, and Westpac.