The good old Microsoft scam that's been going on for years now has grown, many different groups all carrying out the same scam calling people claiming to be from Microsoft and able to fix all their errors for a small fee they mention after they have remote access to your system, recently these con artists have changed tactics and claim to be from Telstra which has been successful for them and prompted Telstra to take the problem seriously for the first time ever.
If you get pestered by these calls you can call Telstra and they will put a trace on your phone line for 30 days and next time the scam artists call a detailed record of the origin of the call will be recorded, you then call Telstra and they can use this information to block that number from reaching you or anyone else in this country, it's not a permanent fix but if everyone does their part, the more often these scam artists have to change their numbers the more they will be discouraged from calling this country.
Also the more Teamviewer log files I have from targets of this fraud the more detailed map I can make of how many groups are actively doing this and where in the world they are. so far two distinct groups, one group are more of an annoyance than anything, the other more sophisticated and malicious.
Also if they gain access to your system, don't ask them to get out, just unplug your internet connection, if they have enough warning depending on which group are calling they may do something to lock you out of your system, I saw this for the first time a few weeks ago and was able to overcome the encryption of the system registry preventing the user from accessing their own computer without having to pay a mysterious fraudster to let us back in.
Don't let anyone tell you there is nothing you can do, especially if you are being called frequently by these fraudsters. The only thing required for evil people to succeed is for good people to do nothing.