There are ROGUE VPN apps out there so by using those you could have installed a RAT (remote access terminal.)
Since you didn't reveal much about your VPN my answer is maybe. In your case, run, don't delay and head to Bleepingcomputer.com since they use a different set of scan tools and will spot these rogues pretty fast.
As to question 3, no if they are any good.
As to 4, no. Too often I find an infection (RAT) or bad hardware or driver.
My Windows 10 OS laptop operates on a WiFi non-public network and I access the internet through a VPN. The machine also has the MacAfee internet security software.
I noticed my mouse making un-commanded moves, clicking, and opening an email message on my machine without any input from myself. I assumed my client machine was being hacked so I shut off the machine. My questions are;
1). Is it likely that my windows 10 machine was being hacked even though it functions on a high caliber business VPN?
2) Is it possibly to hack into the machine just through the Wifi connection which would mean avoiding breaking into the VPN?
3) Would the network logs show proof of the penetration if it was hacked?
4) Is it more likely my un-commanded mouse movements and email message opening was just a windows 10 glitch?
Thank you for any assist provided on this issue.