Telstra now blocking scam texts in the network

Telstra is fighting back against the rise of scam texts by blocking them at the network level.

According to a blog post authored by CEO Andy Penn, the scam filter – part of Telstra’s 'cleaner pipes' initiative – is designed to prevent theft of personal information like banking logins, block the spread of malware, and prevent customers passing infections onto their own contacts.

“We know the number of scam text messages on our network is on the rise – in 2021 we had more than 11,000 reports of malicious texts to Android devices compared to 50 reports in 2020,” Penn wrote. 

The rise is driven by malicious campaigns like Flubot, which infects Android users by offering a link to what purports to be a voicemail. Other versions of the malware advise users of a package delivery.

“That’s why we’ve turned on a brand new feature to find and block SMS scam messages with suspicious links as they travel across our network and stop many of them before they reach your mobile device," Penn wrote.

His post explained that the scam blocks have undergone three months of internal testing.

“Around 2500 employees have taken part and we’ve been successful in detecting and blocking hundreds of scam SMS messages every day.

"Our people on the pilot program told us they saw a reduction in the number of scam SMS messages they received”, Penn wrote.

The technology has been enabled on all messages crossing Telstra’s network, including those of its low-cost subsidiary brand Belong.

“The capability under the bonnet is complex and evolving - it has to be to continue to help outsmart scammers - but in simple terms we’re applying knowledge of what scam text messages look like to block them at the network level," Penn wrote.

“If a SMS looks suspicious, we’ll block it before it reaches the user.

"Automatic machine scanning picks out suspicious content such as malicious links and combines this with other patterns and characteristics like the time, sender, the number of messages sent and the recipient.”

Internally, he wrote, the system sends potential scam messages to human reviewers to avoid blocking legitimate messages.

However, the reviewers never see the details of a message’s intended recipient.

Penn also wrote that “we won’t block commercial messages from banks and other large businesses, government departments, emergency alerts and Telstra applications like MessageBank.”

There is also an opt-out mechanism: text 0438214682 with the words FILTER OFF to turn the feature off.

“If you change your mind you can turn it back on by sending a message to 0438214682 saying FILTER ON," Penn wrote.