Someone claiming to be calling from Telstra to check my internet connection. As I recently got a new phone through them, I thought it might have been a legitimate call, but then asked the caller to email me the relevant information instead (after they started asking whether I had laptop access to check my connection?)

Sounded pretty suss, and my previous dealings with Telstra have been organised, or advised prior, not just a call out of the blue from an unknown mobile number.