Question about firewalls...

If there is a trojan nestled somewhere on your pc with an odd filename...can a firewall still prevent someone from using it to get into your computer?


Also, I ran a trojan and full virus scan both of them scanned and said there were no trojans or viruses on my hard-drive. However, yesterday Norton detected one and was unable to delete or quarntine it. So even though I have done two major scans with two different pieces of software and they said there were no trojans/viruses, I'm assuming the virus that orginally was detected is still there. Should I still format my hard-drive and heed the first warning I got or should I wait a bit or just forget about it since I ran two system scans after this and nothing was detected? Could it have been an error?

Short answer, maybe, it depends on the firewall and the trojan.

Typically a physical firewall sitting between your computer and the internet will allow only outgoing connections, which will normally prevent somebody from connecting to a machine inside the firewall.

A software firewall can't provide that level of protection, but depending on what you've got, may still prevent the trojan from being exploited.

There is a program available at www.download.com called ProPort that scans common trojan ports and can kill any connections that may be trojans. It's pretty handy.

A firewall like Tiny (also available at www.download.com) will allow you to set custom rules based on ports, so you could use that to block common trojan ports, or even set a rule to block all traffic that you haven't explicitly allowed.

Zonealarm and Tiny are supposed to prevent that, but as you all have read Tooleaky has proven that there are flaws.

read it at www.dsinet.org if u want

Alright...Thx guys.:D