I have often seen firewall products make claims like the following:
“It can block the most attacks from worm viruses and trojans”.
is this really true? Can a firewall really block some or most virus infections. Or are they just saying these things, so that we will buy their products?
"It can block the most attacks from worm viruses and trojans".
Firewalls don’t know about those, much anyways. It is an AV program like Avast that detects them.
But if you have an unpatched XP computer, no servicepacks installed, then Avast will have more to detect just from connecting your computer to internet if you have no firewall protection.
So in that sense firewall is blocking attacks by hiding the security holes in your computer. ;D
Firewalls does not act against malware. If it itself is not taken out by malware, it can block the connection some malware makes inbound or outbound, and can help in this way to suspect malware activity. There are other tools for that too, learn how to use netstat from Command prompt e.g. nestat -a netstat -an to see what connections are made from your machine. The main detection of this malware is done by a good resident AV product, like our AVAST is. A program like System Safety Monitor can warn you when programs behave in a way they are not supposed too. In this way you can have an indication too. Special anti trojan software, and A-squared is a good solution, can be a welcome addition in finding trojans and backdoors. But the best defense against infections of this nature is and will always be “A good working human brain”.
The word Trojan by its nature is something invited but contains something, an unexpected surprise. A firewall will not stop any user initiated download, so if that download contains some extras they too will get through, you need an AV and malware software.
You are often invited to download the latest, greatest piece of software since sliced bread, that will make your life so much easier and wham you find adware/spyware invited into your system. Exercise caution in what you download.
Firewalls can block some viruses, but not enough to ensure any degree of safety or confidence.