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.

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.

Dynatrance data expert Dave Anderson said Australian connections to the websites became unusually slow.

“While not as severe as the US, Australian sites were definitely experiencing performance problems as a result of the DDoS attacks overnight,” Mr Anderson said.

“Of the sites we’ve monitored, we can see that the average DNS connect time spiked to about 8 seconds, when normally it would average 3 milliseconds.

“While it’s a bit unlucky for these Australian sites to have been hit, it’s a wake up call for everyone with an online presence. You’re on 24 hours a day and these performance issues will be part of the daily digital life ongoing.”