The attacker, named in local media as Ihsas Khan, was today charged with committing a terrorist attack and attempted murder after the alleged attack on a 59-year-old man in the suburb of Minto yesterday.
The victim, known as Wayne, was allegedly stabbed while walking through a reserve, suffering serious injuries to his hands and body.
Witnesses heard the accused man shouting in Arabic during and after the attack. The victim managed to run to a nearby home to seek help.
She said it was a deliberate act, it resulted in a person receiving extremely serious injuries.
More From This Section
"It is possible the man attacked the stranger in an attempt to lure police and attack them," she said, adding investigators have found information to suggest the man had planned to commit an attack yesterday that was inspired by Islamic State.
The attacker, who was denied bail after a court appearance today, was not believed to be connected to any terrorist groups known to police, Burn said, but underlined that the type of threat he posed was a new challenge to authorities.
"This is the new face of terrorism. This is the new face of what we deal with," Burn said.
The alleged stabbing came two days after a teenage boy was charged with making threats at the Sydney Opera House, and both incidents followed an IS call to target high-profile Australian sites.