This occurred when I was not on-line at all and puzzled me.

I used Photo Gallery to import about 20 photos to a named file I had created.

On ending by CLOSE,  I saw a small green icon in the notification area.

R click and message "your system(?) has been accessed"

Followed this through path suggested by/through MS links nothing made sense at all.

Only accesses mentioned pertain to HP, I use an HP laptop.

Any ideas what is/was/had happened( was not on loopy juice!!)

HP Pavilion dv6, Win8.1, IE11, MS Defender

Over to you!

Brian