This is a scam, be aware..!!
We received a call this evening from a lady (with Indian accent) posing as an employee from Telstra Technical Department advising that our internet was going to be disconnected immediately due to our internet being hacked on a daily basis.. We were immediately suspicious as our internet is through a different provider but we didn't mention that just to see how far this conversation would go.
When we questioned this situation the lady hung up but then called back after 5 or so minutes.. She offered that in order for us to prevent the disconnection from happening to jump on our computer and follow her instructions. We obviously didn't follow her instructions as it was clear that this was a scam.. We questioned her some more and also asked for her name and number so we could call back when my brother came back home (as he's more technically minded) and at that point she hung up again.. No call back..

I called Telstra's scam and phishing line to report this and they advised that they are aware of such situations and because calls are made from overseas using internet telephone numbers they unfortunately cannot be traced..