How does an antivirus detect trojans/viruses and block incoming/outgoing traffic?

Question

Antivirus

Interested in both its interception - on what principle it is organized, and traffic blocking.
In general, for any tip in this area, at least literature, what to read where to go, I will be very good. grateful. While not at all in the subject, I would like to understand.

Answer 1

https://www.sans.org/reading-room/whitepapers/int...