With the so-called Islamic State (IS) group on the brink of collapse, new details are emerging of how Australian operatives working from the other side of the globe helped to defeat the terrorists.

Key points: Head of the Australian Signals Directorate Mike Burgess will make a rare public address, speaking at the Lowy Institute

Head of the Australian Signals Directorate Mike Burgess will make a rare public address, speaking at the Lowy Institute New information will describe how Australian operatives shut down Islamic State communications in the Middle East

New information will describe how Australian operatives shut down Islamic State communications in the Middle East Mr Burgess will reveal how the ASD worked with Coalition partners to damage the IS media machine

In a rare public address, the head of the secretive Australian Signals Directorate (ASD) will today declassify details of operations where cyber spies worked remotely with the Department of Defence to destroy IS communications in the Middle East.

"Just as the coalition forces were preparing to attack the terrorists' position, our offensive cyber operators were at their keyboards in Australia — firing highly targeted bits and bytes into cyberspace," ASD director Mike Burgess will reveal in a speech on Wednesday, the details of which have been obtained by the ABC.

"Daesh [Islamic State] communications were degraded within seconds — terrorist commanders couldn't connect to the internet and were unable to communicate with each other."

In another previously secret operation, the ASD worked with coalition partners to damage the IS media machine.

"We locked the terrorists out of their servers and destroyed propaganda material, undermining Daesh's ability to spread hate and recruit new members," Mr Burgess will tell the Lowy Institute.

"In these operations, cyber operators at computers in Canberra helped fight and defeat terrorists on the other side of the world."

An Egyptian IS fighter in Syria after surrendering in early March. ( ABC News: Suzanne Dredge )

The ASD director will also reveal how an employee impersonated a terrorist online to convince a wannabe overseas Australian jihadist to move to another location where he could be captured.

When ASD was first alerted to the situation, a specialist team of linguistic, cultural and behavioural experts was quickly formed and a sophisticated plan was hatched.

"The risks were significant and the stakes were high. If the terrorists didn't accept the newcomer, they would likely execute him," Mr Burgess will say.

"If the terrorists did accept him, he would be further radicalised and trained to kill. It was literally a life-and-death scenario."

Sorry, this video has expired Almost 1,000 Islamic State fighters in Baghouz surrendered to the Syrian Democratic Forces earlier this month.

Young Aussies who 'can keep a secret' urged to join ASD

The head of the team was a "highly trained young woman" who used "a series of online conversations to gradually win her target's trust".

In his public speech, Mr Burgess will also issue a plea for more ASD recruits, to fill roles such as linguists, software developers, analysts, code breakers and behavioural experts.

Mr Burgess will say, despite public perceptions, the organisation's most experienced covert online operators were women, and employees can come to the office dressed casually.

"Some of our people wear sharp suits to work … and quite a few wear the hoodies and jeans that you might expect to see in a tech start-up rather than the public service," he will say.