Some scam company, they called my intern and he asked me to answer. I answered and they asked my name to 'verify' then they tried to tell me my PC has problems. I explained I don't use Windows and they said it was my MacBook. I told them I don't own a MacBook either (much to the amusement of the others in the IT office at the time) and they started getting frustrated. Fast forward about 45 minutes of screwing with them we had an issue in the server room so I asked they take the number off their list and hung up.
I am a highly certified computer programmer that users a self built Lynx laptop with virtual desktops inside it. If they call get off their list and if you're concerned take your laptop to a shop (or the geeky friend who knows everything about standard computer stuff) and have them look it over.