Customers in Queensland, New South Wales, Western Australia, South Australia and Victoria woke up Tuesday morning to find their iPhones, iPads and even desktops and laptops displaying a message that said "Device hacked by Oleg Pliss" and demanding $100 to unlock the device.
Experts say that the hack could have taken advantage of Apple's "Find My iPhone" section in its cloud service, iCloud. Apart from the message, the hackers also added a passcode preventing users from restoring their phones using iTunes.
The hack suggests that the attackers gained access to users' Apple ID credentials gaining access to the "Find My iPhone" section on iCloud.
Vodafone and Optus, carriers in Australia, said that they had received no complaints from customers so far. Telstra said that they had received reports of the hack and have forwarded the complaints to Apple.
"In the meantime customers who need assistance can contact Apple Care," Telstra said.