Australians are putting their trust in supermarket giants while keeping a wary eye on some poorly performing businesses after a horror year of hacks and travel disruptions.

The latest Roy Morgan ‘Net Trust’ rankings show the top five most trusted brands – all major retailers – are unchanged for a fifth straight quarter. These include Woolworths, Coles, Bunnings, Aldi and Kmart.

At the other end of the spectrum, distrust for Optus and Medibank has soared, landing Optus second place in the most distrusted brands in Australia, rising 15 points to take the spot from fellow telco giant Telstra.

Medibank placed 14th in the list of the country’s most distrusted brands, after previously ranking as a trusted brand.

This comes after both Medibank and Optus suffered severe data breaches in 2022, in which millions of customers had their private data accessed.

This forced many to replace important ID documents such as passports and driver’s licences, and millions of current and former Medibank customers faced the possibility of having their medical details – ranging from drug addictions to sexually transmitted diseases – leaked online.

On Tuesday, a class action lawsuit was filed against Medibank over the data security breach; the health insurance provider is set on defending against the claims.

National airline Qantas also took a nosedive in rankings over the past six months, falling 31 places from its position as the ninth most trusted brand to the 40th.

Qantas’ 2022 was plagued with complaints of poor customer service, flight delays, cancellations, and rising prices.

Much of the blame has been placed on the airline’s decision to sack at least 6000 workers at the start of the pandemic, leaving it struggling to meet traveller demand when borders opened.

Although Qantas started off 2023 on a high after managing to provide the best on-time performance of major domestic airlines in October and nabbing the title of the world’s safest airline, the year quickly soured thanks to a series of flight turnbacks.

Twitter has also jumped up most distrusted rankings, from 16 to 11 over the December quarter, following Elon Musk’s purchase and subsequent shake-up of the company.

Roy Morgan CEO Michele Levine said distrust presents dangers for brands in the wake of scandals.

“What we see with brands that suffer major scandals is that once distrust takes hold, it is very difficult to curtail,” she said.

“We saw it with AMP and the big four banks following the royal commission, and we are still seeing it with Harvey Norman.

“More than two years after the JobKeeper scandal, they are still ranked in the top 10 most distrusted brands in the country.”

Roy Morgan data scientists analysed nominations from more than 22,000 Australians to identify the nation’s most trusted and most distrusted brands.