The internet was down for Telstra customers across the country on Sunday thanks to a domain name server (DNS) issue that overwhelmed the company’s network infrastructure.

Telstra quickly made headlines when it attributed the outage to a cyber attack.

“Some of our Domain Name Servers (DNS) used to route your traffic online are experiencing a cyber attack, known as a Denial of Service (DoS),” Telstra said.

“Your info isn't at risk. We're doing all we can to get you back online.”

DoS attacks occur when a bad actor tries to overload a network by sending a massive amount of simultaneous requests, disrupting the service.

Much of the country has been on high cyber alert since the Prime Minister’s announcement that Australia’s computer systems were being targeted by “a sophisticated state-based actor” in June.

Even the Telstra outages website was unceremoniously offline during the incident.

Savvy social media users shared methods to solve the problem through bypassing Telstra’s DNS in their router or device in favour of Google’s address book.

By 2.30pm, the issue was largely resolved with Telstra proudly announcing it had blocked “the malicious traffic attacking some of [its] services” and that everything was working as expected.

Then the ISP admitted the so-called “malicious traffic” that formed the alleged DoS attack was likely just a mass of customer requests caused by an issue with its DNS.

“The massive messaging storm that presented as a Denial of Service cyber-attack has been investigated by our security teams and we now believe that it was not malicious, but a Domain Name Server issue,” Telstra said.

“We're really sorry for getting in the way of your weekend plans.”

The incident had echoes of Government Services Minister Stuart Robert’s infamous press conference claiming the MyGov website crashed in March due to a “distributed server attack on [its] main channels”.

He later admitted the system was just receiving an unaccounted-for traffic burden due to the number of people logging in to sign up for Centrelink payments at the height of the coronavirus pandemic.