Auckland (New Zealand): An Auckland man is seeking answers after a sophisticated SIM swapping scam led to $19,300 being withdrawn from his joint bank account in two transactions. Jade Wang, a customer of Kogan Mobile, received a text message from One NZ on April 24 saying his phone number had been swapped to a new SIM. The alert advised him to contact One NZ if he had not authorised the activity.
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Warning message followed by loss of service
Wang called One NZ after receiving the notification, but was told his number was not registered with the provider before being placed on hold. His call was later disconnected while he waited for the operator to return. As he was not a One NZ customer, he initially thought the alert may have been a system error.
Around 5pm, Wang noticed that his mobile phone was out of service. He later contacted his wife, who found that $19,300 had been withdrawn from their joint ANZ account in two separate transactions. The couple then contacted the bank, filed a police report, reported the loss of photo ID and blocked his bank cards.
Bank inquiry found password reset through mobile code
The investigation found that Wang’s internet banking password had been reset using his customer number and a code sent to his mobile number. The code was then used to verify the request. After two payments totalling $19,300 were transferred, ANZ held a third payment while additional checks were carried out.
According to the bank’s report, ANZ called Wang’s registered mobile at 5.38pm and spoke to someone claiming to be him. The bank said it had concerns during the call and suspended his internet banking. On May 6, the bank that received the funds returned $19,300 to Wang.
Wang said he was shocked by how quickly the SIM on his phone had been hijacked, adding that he lost control of his mobile number in around 15 minutes. He said the short window of time left him with little opportunity to respond.
Fraudulent SIM swap confirmed
Wang received a new SIM card from Kogan Mobile several days after the incident and said he was told an investigation had been launched. However, he said the results of the investigation had not yet been shared with him.
In an email seen by RNZ, One NZ said the alert sent to Wang had been generated because of activity on its network. The company said Wang’s initial call to One NZ had been disconnected because his SIM was in the process of being accessed by a third party. When a One NZ agent tried to call him back shortly afterwards, the company said they could not reach him as his number had already been transferred to another SIM card.
One NZ spokesperson Nicky Preston, who also answered RNZ queries on behalf of Kogan Mobile, said the country’s largest wireless carrier had concluded that Wang had suffered a fraudulent SIM swap. Preston said the Office of the Privacy Commissioner had been notified of the breach. She said One NZ had introduced a system-enforced 15-minute delay on SIM swaps to give customers advance warning of potentially unauthorised activity while allowing legitimate requests to proceed.
Wang warned mobile phone users to remain vigilant about unusual alerts and said people should act quickly if they receive suspicious messages. Paul Brislen, chief executive of the Telecommunications Forum, said this type of fraud was very unusual and advised people not to share identifiable personal details on social media, including home addresses, phone numbers or IRD numbers. He also recommended using complicated passwords and app-based two-factor authentication where possible.
