No agency '100 per cent safe' from cybercrime, ACCC warns after Optus hack

The ACCC's deputy chair Delia Rickard has warned Optus customers to regard all new contacts with suspicion following a massive data hack.

The cyberattack, carried out by an unknown party, saw the personal information of potentially millions of Australians stolen.

Rickard said the hackers had access to peoples' dates of birth, drivers licences, passport numbers, and email addresses.

READ MORE: Grandmother's very Aussie run-in during Queen's funeral

"These are all the things that you need for identity theft and also all the things you need to personalise a scam and make it much more convincing," she said.

She said there were steps people could take if they had been affected.

"Ensure all your devices are secure. Make sure you have two factor authentication on all your banking," she said.

"If you suspect fraud, get a ban on your credit records.

"I think one of the really important things is, when you are contacted by anyone that you are not expecting, whether they say they are the government, your bank, any identity at all, when you are dealing with people remotely you will never know who you are dealing with.

"And because the scammers have so much data about you they will know your name, they will know your age, they will be able to personalise scams and we know that when somebody calls you and has your name and a few details you are much more likely to trust them. So I think be highly sceptical as well."

Rickard urged people to check with their banks whether anybody had been applying for loans in their name.

And she warned people that it wasn't just Optus customers who were vulnerable.

"In this day and age cybercrime is huge and whilst most agencies are spending a fortune to protect themselves, you can't say that anyone is 100 per cent safe," she said.

Find more information on the ACCC website