As a long time Windows user, I have gotten used to running a program called Spyware Search and Destroy every day to clean out programs that are inserted onto my hard drive by malicious advertising web sites. These include crummy registry entries, tracking cookies, and even downloadable programs.

Spyware Search and Destroy (some prefer Adaware) find these items and blow them off the hard drive.

I also used Zone Alarm as a software firewall to protect against trojans and these spyware programs from being allowed to phone home, because it is a two-way firewall and blocks outgoing traffic program by program and pops up requests to allow programs through. Plus, it's free, which is nice.

But I digress...

1. Is Linux vulnerable to spyware, and to what extent.

2. If yes, is there an anti-spyware program for Linux?

3. If no, why is it not vulnerable?

Obviously there is no registry, I guess tracking cookies could still work.

Currently I have a router/modem combo installed providing firewall protection. Do I still need to enable IPtables? The shields up web site says I am in stealth mode except for responding to ping requests.

And BTW, I forgot to mention that I think spyware really stinks and that the people who make web sites install this stuff should go to a special place in hell when they die. I am hopeful Mozilla is less friendly to these ad/privacy violating web sites.

1. Linux is vulnerable to spyware, but not to the extent that Windows is. A big factor in this is the open-source nature of many apps. Unfortunately, there are some apps for Linux that are distributed in binary only format. Trust is a big concern when dealing with those developers. Of course, any developer that embeds malicious software is going to "lose face" in the Linux community.

2. There are some apps that attempt to minimize the effects of malicious software. I've attempted to build a directory of useful software. On the Linux side, the anti-spyware stuff usually falls into the filtering proxy group. Hope it helps...

Linux is much less vulnurable to the kind of spyware that installs without you knowing when browsing the Web (using security flaws in IE etc). Still there's a possibility to have such software when you install binaries not from trusted sites.

Even when you're using a router, iptables may be a good idea. Especiall when you have more than one machine (and it's a must if there are more people in your local network).