Although its brown, i don't think its a BTF, It lacks the soft stripes at the sides.
If it came in banana box, probibly not a BTF as they aren't much in the top end of Aus.
My best guess is one of these two little fellas,
Litoria meiriana
Rockhole Frog
Litoria revelata
Whirring Tree Frog
I Highly reccomend you call the Victorian frog group, banana box rescue (03) 9742 3764 (or 9742 FROG) . They will come and pick it up free of charge and quarinteen it. They can also identify exactly what species it is.
It could have disesase on it that may travel to other frogs,thats how the chytrid fungus got around, and frogs world wide are being wiped out cause of it.
It may require specialist care, ya don't want the poor thing dying cause it needed a specific heating or uv light requirement.
Love the cute little fella,
Sarah