My firewall got stupid, please help anyone?

[Invalmima]

Cheers

I am a stupid when it comes to macs.  I downloaded a mcafee antivirus...so ftware, that was from the university I go to. And after that and a full virus scan, I could no longer use firefox or yahoo messenger.  I got rid of them and downloaded them again, restarted my desktop pc a few times, but nothing is working.  I keep getting a message that something needs to be done with my fire wall and HTTP, HTTPS, and FTP ports.

Recommendation s any of you?

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