An unemployed Sydney teenager who tried to blackmail nearly 100 hacked Optus customers into transferring him thousands of dollars saw it as an opportunity to make "quick money", a court has been told.
Dennis Su, 19, was arrested last month after Australian Federal Police (AFP) investigated text messages that were being sent to Optus customers demanding they transfer $2,000 to the bank account of his younger brother.
Ninety-two customers received the messages, which threatened to use their personal information for financial crimes if they didn't comply.
Nobody transferred the money.
Today in Downing Centre Local Court Mr Su's lawyer entered pleas of guilty to two counts of using equipment connected to a network to commit a serious offence.
According to the agreed facts, Mr Su first accessed the hacked data on two forums and saved the contact numbers of 100 Optus customers to his iPhone.
He told police his intention was to "scam victims".
The court documents reveal that when one recipient of the text message replied with an emoji, Mr Su revisited the forums and then identified that victim by their full name "to give himself credibility".
The victim later responded: "The police have your details. And I have nothing you can gain. Good luck."
Mr Su admitted to sending the messages "because he was having a difficult time being unemployed and he saw an opportunity to make 'quick money'," the court documents said.
The magistrate was today told Mr Su had written a letter of apology to the court.
Two reports from a counsellor the teenager has been seeing since the crimes were also tendered.
Magistrate Susan Horan told the court a sentencing assessment report was required before the case could be finalised.
She noted the maximum penalty was 10 years' imprisonment.
Mr Su wasn't accused of being behind the Optus hack but was charged for attempting to benefit financially from the thousands of stolen records dumped online.
AFP officers traced the bank account mentioned in the text messages and seized a mobile phone linked to them when they searched a home at Rockdale on October 6.
Mr Su will be sentenced on February 7.
