Said they were from NBN and were trying to get me to test my internet settings because my internet had been changed from private to public and it was being used by multiple other people or something. He asked me to type in a URL on my phone, which I was suspicious about. I asked why I hadn't received an email about this and he said it wasn't safe to email given my internet was compromised, but he gave me my (old) email address to verify, which triggered more suspicion because normally companies never give out information unless you give it first. I asked if he could confirm what area the account was registered to and he said it was in NSW, where I've never lived. I said that and he hung up immediately, so definitely something dodgy!