Odd behavior has got me concerned...

[Rubyfocus]

Here's what's happening:  Sometimes I'll leave my computer on while I work around the house, etc.. When I return to the computer, I can see that my browser is up and there's several windows open to usually two websites: PayPal and Dundle. The first time this happened, I didn't think too much of it and just forgot about it. Then, it happened again. PayPal and Dundle up on my screen. So apparently, someone is able to remotely activate my browser and direct it to these websites to do who knows what.  I didn't think that this was even possible to do, but apparently it is.  Does anyone know how I can keep this from happening?

[maratsade]

Maybe this will help: https://www.wikihow.com/Detect-a-Remote-Access-to-My-Computer

Also, change your WiFi passwords, including the  password for the guest WiFi. 

Is there no one else in your house who could be using your computer? 

[GabeU]

It's possible that your computer has been infected through a phishing attempt, giving the 'bad guys' access to it. 

Were it me, I'd perform a clean install of Windows, then install all add on programs fresh, not from your backups.