There are fears Westpac has fallen victim to a cyber attack after customers were met with online blackouts for a third straight day.
Wednesday’s disruption impacted millions of customers, with one telling 7NEWS they could not access their cash and could not even pay for petrol because their cards were not working.
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Westpac has not revealed what is behind the ongoing disruptions, which also blocked customers from its mobile app and online services for hours on Monday and Tuesday.
Monash University cyber security professor Nigel Phair described the outages as “extremely rare” and “extremely unusual” for modern banking systems.
7NEWS understands the ongoing issues have been referred to the government’s lead cyber security agency, with the major concern that the big four bank has been compromised.
“When something like that happens it enlivens the cyber security part …