This article originally appeared here;

On Friday, a massive distributed denial of services attack (DDoS) knocked out access to a number of major websites. Although the incident appeared to target the U.S., its effects rippled out internationally.

While facts are still emerging, it seems the attack centred on Dyn, a domain name systems (DNS) provider that essentially acts like a phone book for major sites such as Twitter, Amazon, Tumblr, Reddit and Spotify.

The DDoS attack aimed a firehouse of traffic at the company, apparently making use of millions of insecure internet-connected devices like baby monitors, digital video recorders and smart fridges, rendering it unusable.

What’s worse, all those Internet of Things (IoT) devices could have been located anywhere, including Australia.

There were reports of users unable to access sites in Europe, and according to the digital performance monitoring company Dynatrace, Australian sites affected included banks such as ANZ and Westpac, and supermarkets Coles and Woolworths, among others.

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