Most major desktop, and most commercial distros include chunks of proprietary code ("binary blobs" so to speak), mainly device drivers.
There are many AV products, several commercial and the open source ClamAV for linux. They are often sold to server operators as they currently serve more to protect windows clients than the linux server.
I shan't spam my opinions regarding which OS has fewer library errors, less cryptic error messages, stability, reliability, etc. It suffices to say that they're all crap. I just think linux is less crap than the alternatives at the moment.