The Optus brand suffered a $1.2 billion blow after last year’s cyberattack, plummeting down the rankings of Australia’s most valuable brands, that was topped by Woolworths, Telstra and Commonwealth Bank.

Medibank’s brand would also have likely been hit hard by its massive data hack, which wiped $1.8 billion from its market value in one day, but Brand Finance’s calculations for its 2023 list were compiled in early October – two weeks before the health insurer’s breach.