Is Peter Williams a real employee or a hacker?

I received a phone call from Peter Williams introducing himself as technical support manager and referring me to do a google search of his name. Indeed I have found a page with an employee called Peter Williams, seemingly connected to Microsoft technical support. The person claimed that my IT address was used by others without my permission and he was going to help me fix this issue. They asked me to install TeamViewer and then asked me for the ID and password that showed up after installation. I hesitantly shared this with them, but they kept asking me again for this information, as if struggling with connection. I got suspicious and closed the application. I hope it's not too late...