Incident & Breach Response
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Security Operations
After Optus, Another Australian Subsidiary Reports a Data Breach

Mobile network carrier Singapore Telecommunications is dealing with its second Australian subsidiary data breach in a handful of weeks now that IT consultancy Dialog Group has seen some of its internal data published on the dark web.
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The two incidents are joined by a third affecting the global communications giant – the additional incident being a hacker forum posting containing 74 gigabytes of data purporting to include confidential company documents, employee email addresses, work orders, stock requisition and business application forms and more.
Dialog is probing the unauthorized access of company data, which could affect up to 20 clients and around 1,000 current and former Dialog employees.
Singtel’s first breach occurred at telecom provider Optus following an incident where the personal information of 9.8 million Australians was potentially exposed after the company detected “unusual activity” on its network (see: Optus Attacker Halts AU$1.5 Million Extortion Attempt).
The Singapore company says the two Australian incidents appear unrelated. While SingTel acquired Optus in 2001, it added Dialog to its portfolio in AU$325 transaction that closed in April.
Dialog says it detected an undisclosed threat actor’s malicious activity on Sept. 10 and shut them down as a precautionary measures. Last Friday, it says it became aware “that a very small sample” of company data including some employee personal information was available on the dark web.
“Ongoing investigations showed no evidence of unauthorized downloading of data,” the company says.
Dialog’s clientele includes the National Bank of Australia, Virgin Australia, and several governmental and healthcare departments of states like New South Wales, the Northern Territory and Queensland.
More Data Breach Woes for Singtel
SingTel must also deal with a hacker who posted data in a data breach forum that the company confirmed is its leaked data. The leak stems from a zero day vulnerability in file transfer application Accellion FTA used in a string of breaches in 2021 (see: 2 More Breaches Tied to Accellion File Transfer Appliance).
At the time, Singtel determined that personal information of its 129,000 customers and 23 enterprises had been exposed in the breach. Bank account details of 28 former Singtel employees and credit card details of 45 employees of a corporate customer were also exposed.