Can a hacker access your laptop via a cell phone?

I've been suspicious of oddities on my laptop and cell phone the past 2 weeks. I rarely utilize the internet - but I am on it for long periods when I do. Lately, I noticed an odd command prompt I nor anyone else placed there. Can't access the prompt yet and I run an anti-virus before and after I finish. I also noted a substantial increase in temporary internet files I did NOT put there Thus far as I am aware, I am the only administrator and I run on a VPN. I was using an ethernet - but that stopped functioning for some reason and I had to flip public wi-fi, then back to private. My phone is the only wi-fi allowed and I suspect someone somehow accessed it via data from my phone with some type of command prompt I'm not familiar with - but I'm not a computer jockey or tech specialist in that respect.