Remote access
Just a thought - our more technically advanced colleagues will help out here. You might well have done something to either your pc or your modem/modem router to enable the remote access that helped you.
For your own security reasons, you might wish to un-do whatever you did so that remote access is turned off, if you haven't already done that.
Whenever I've enabled remote access so that technically literate folk can help me, they've always told me to turn it off.