Ring.
Me: Yes?
Caller: This is Microsoft Security. You are downloading a virus to our server and we need access to your computer to ensure it causes no further problems.
Me: Really? Well, first, who is the head of security for Microsoft?
Caller: That’s none of your business.
Me: Well, he’s a friend of mine and you should know his name if this call is legitimate.
Caller: I’m not allowed to divulge that information. Could you please provide us with access to your computer…
Me: And second, you have reached the former Information System Security Officer for the National Defence Pay System.
Click.
Never had a problem since.