The simple question is: Does the Avast Network Shield detect the same threats as Comodo does, or does it add additional security measures?
I can post 'technical' info about it:
Network Shield is a protection against known Internet worms/attacks. It analyses all network traffic and scans it for malicious contents. It can be also taken as a lightweight firewall (or more precisely, an IDS (Intrusion Detection System).
Network Shield protects you from internet worms that spread themselves via various security holes in your system. Typicaly these kind of viruses don't infect files but instead they attack running processes on your PC (either Windows components or some server programs like SQL Server, IIS etc.). These kind of attacks are not easily catched by ordinary antivirus during file or mail scanning. It is not a duplicate work with Standard Shield.
It scans incomming packets which are sent to particular ports (like 445, 135, 5554, ... where an attacker can exploit your computer; it's the protection against blaster/sasser/... worms). The network shield does not block or slow down other network traffic on other ports (NetShield ignores them).
