Are you virused appears you might be as you asked here re a possible infection.
1. try restoring the PC to a time before all this started remenber you will lose some changes and maybe other programs that happened in that period.
2. Run mcafee in safe mode
3 referring to this link McAfee Communities: Anti-Spyware/Malware & Hijacker Tools
run after downloading stinger and getsusp ( add your email to the preferences so Mcafee can contact you then download and run the free malwarebytes from the link provided.
4. After above you might have an idea what you have picked up and we can expand on what to do.
The firewall issue is 99% possibly caused by the issues you are having. We can fix the firewall only after the malware is removed. I went through this with my daughter's laptop only last week all worked out in teh end.