MrIntrepid said:
You're Zevism, don't trust anyone, don't open any links and don't download anything from anyone. I didn't think it was this easy to inject yourself into someone's life but apparently it's even possible for viruses to be executed from PDFs.
Totally possible. Any files of the source you are unsure of you should open in sandbox: https://sandboxie-plus.com/ Other software exist also, but this is what I have used in the past.
That way the executable stays inside a "box" and anything malicious inside of it can not spread to rest of the system, unless allowed by the user.
You should also reinstall your operating system from the scratch since it has been compromised. If you can not do that then look for instructions online, or ask for someones help who knows how to do that. Consider Linux environment and always be wary: The best firewall is located in front of the screen. You can download various Linux distributions free of charge online.
Hope this helps a bit. Good luck in getting rid of the pest.