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Up to 10 Million Australians affected in Optus hack


Cyberattack detected by Optus 

Hackers accessed the data of up to millions of Australians, including names, addresses, phone numbers, and email addresses for many. Driver’s licence, passport and Medicare numbers were also accessed for a smaller number of people. 

CEO of Optus, Kelly Bayer, has revealed that customers dating as far back as 2017 are caught up in the breach. Although the hackers’ access has been removed, it is still unclear how much data they stole. 

This hacker claimed he obtained the data from an unauthenticated application programming interface (API) – software that connects two different systems – requiring no login details. 

‘Largest ever’ attack on an Australian business 

In terms of severity and number of people affected, Optus’ data breach is one of the biggest and most significant.   

The threat actor’s initial post on a hacking forum

10,000 records leaked 

The attacker later uploaded a file containing 10,000 records to a data breach website on Monday night and threatened to leak 10,000 records daily for the next four days unless Optus paid $1m in cryptocurrency. 

It contained names, dates of birth, emails, drivers’ licence numbers, passport numbers, Medicare numbers, phone numbers and addresses. Additionally, it included more than a dozen government email addresses, including four from the defence department and one from the Prime Minister’s Office. 

Hacker allegedly deletes data 

In the evening of Tuesday morning, the alleged attacker had apparently changed their mind, deleting their posts and claiming to have also deleted the Optus data. 

It is impossible to prove that any data has been deleted, despite the removal of the posting. Those who acquired the data of 10,000 Australians during the leak still have access to it. 

Small attack, big consequences 

This is one of the biggest hacks in recent Australian history, and unfortunately isn’t the first time Optus has had customer data leaked. This is the fourth cyber-attack on Optus since 2019, and in 2020, 50,000 Optus customers had their data leaked.    

Cyber breaches for large firms were once considered minor disruptions. Today, unsophisticated cyberattacks on firms like Optus can have disastrous financial and reputational harm.  

Moving forward 

Those whose identity documents were compromised by the alleged Optus hacker need to replace them urgently. 

Customers notified by Optus with compromised driver’s licence details are strongly advised to apply for a replacement, according to NSW customer service minister Victor Dominello. 

Victorians will also be able to get “free” licence number replacements and flag their licence records to prevent future fraud. 

Other states and territories are making similar arrangements, which could cost Optus millions of dollars. 

Ahmed Khanji

Ahmed Khanji

Ahmed Khanji is the CEO of Gridware, a leading cybersecurity consultancy based in Sydney, Australia. An emerging thought leader in cybersecurity, Ahmed is an Adjunct Professor at Western Sydney University and regularly contributes to cybersecurity conversations in Australia. As well as his extensive background as a security advisor to large Australian Enterprises, he is a regular keynote speaker and guest lecturer on offensive cybersecurity topics and blockchain.


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