Cyber intelligence firm Dulvn has revealed that 31,000 passwords belonging to online accounts at Australia's Big Four banks have been exposed. 

At least 14,000 Commonwealth Bank, 7,000 ANZ, 5,000 NAB, and 4,000 Westpac customers' passwords are available on Telegram and the dark web.

Senior Application Security Engineer at Dvuln, Noah Farmer, told Sofie Formica on 4BC Afternoons, "If you do think you're affected by an Infostealer, the best thing to do is keep everything up to date."

"You can install antivirus and anti-malware software, but that alone is not a silver bullet."

"The best thing to do is to be vigilant for any signs of compromise...make sure you have a clean device to access your accounts," Mr Farmer continued. 

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