Prior to June hackers successfully breached “a series” of Australian merchants’ computers and gained customer card data, according to the Australian Federal Police.
The AFP has not disclosed how the systems were breached or how many card holders were affected, but on Wednesday claimed to have found the cause of the breaches at a series of merchants.
Police were continuing an investigation that commenced after a financial institution alerted it on June 8 to “suspicious transactions”.
It was not clear whether the computer systems breach affected credit or debit cards and merchants have not been identified.
Australian financial institutions were in the process of refunding affected card holders, according to the AFP.
The Australian Payments Clearing Authority warned in June that Australia’s card not present fraud rates were expected to rise due to the increased adoption of chip and PIN technology. Credit card fraud is currently 62.8 cents in every $1000 transacted.
It also pointed out requirements under the Payment Card Industry Data Security Standard, which is enforced to varying degrees by Visa and MasterCard.
Cosmetics retailer Lush in February advised customers to change their credit cards after its systems were breached, while more recently, Westpac, Commonwealth Bank of Australia and Bendigo Bank collectively reissued over 10,000 cards after a merchant was compromised.