Apple users are being warned of recent cybercriminal attacks, where phones and tablets have been held for ransom.

When it happens, users are woken with an alarm-like sound and then a message “Your device has been hacked by Oleg Pliss” is displayed on the device.

For Apple users this should be a wake-up call, and a push for users to turn on the device’s two-factor authentication (2FA) for Apple ID credentials, says Carey van Vlaaderen, CEO of Eset Africa. To date, only users who do not have 2FA switched on have been targeted.

Apple’s 2FA allows a user to authenticate using a password, a four-digit PIN (verification code) texted to a trusted device at each login, and also generate a 14-digit recovery for emergency.

“Apple users should be extra cautious,” says Van Vlaanderen. “Although attacks have been confined to Australia and New Zealand, cybercriminals are not deterred by geography, and the chances are that they will move out of these areas and shift their focus to other countries.”

She adds that if South African users do receive ransom demands, they shouldn’t pay up and there is no guarantee that the hacker would restore access to the affected device once the ransom is paid.