I have been using Microsoft Planner. My computer is protected using Norton, and is on a daily deep scan routine. On Microsoft Planner, there is a customer service feedback form, basically asking if I would recommend planner. There are two questions, the recommendation question, and a box to include your email address.
When I started filling the email address, the email Email address removed defaulted into the address box. I have never accessed this domain, and am wondering whether the customer survey itself has been hacked.