[fingal]

Here at linuxforums.org we are often asked about the
potential threat of a virus or malware attack. This
short guide is designed to answer some of your questions so
that your experience with Linux will be both safe and
enjoyable.

Generally, you will find that by using Linux you
are less likely to be the victim of a virus attack, but
you still need to take some basic precautions.

Here are some previous threads which deal with the question
of virus protection for Linux users:

Virus Software For Linux
What is the BEST anti-virus program?

Your security can also be compromised by the presence of a
'rootkit' on your system. This is a set of software
tools installed by an unauthorised third party to gain
access to a computer. Perhaps the best way to detect a rootkit is
to install and run Rootkit Hunter

As you may have realised from reading some of the threads
listed above, up-to-date anti-virus software is readily
available for Linux systems. One of the best known is
Clam-Av which is pre-installed on some distros. It can be downloaded
from this link.

There is also a useful graphical front end available for
Clam-Av, and this can be found here.

Many Linux users ensure that they have extra security by
installing a firewall. Here are some previous threads which
discuss this:

Is a firewall really needed?
What's a good firewall that can be installed as a RPM?
What's the best firewall distro?

As you can see, there are a number of different
firewalls which will help to secure your computer. Here is a
short selection complete with web links:

Guarddog - A good firewall to begin with. Not too hard to install or configure.
Smoothwall - This can be used to turn a redundant PC into a firewall.
Shorewall - A high-level tool for configuring Netfilter.
IPCop - Capable of displaying network traffic statistics.

As you will have realised by now, security is a big subject,
and this guide cannot hope to cover all your questions.
There are entire sites devoted to this, and here are a
few for you to visit:

Linux security.com
Linux-Sec.net
Security Quick-Start
Security Report: Windows vs Linux

As you become more proficient you will want to consider
taking further steps to deny access to system crackers.
To check the strength of your passwords try 'John the Ripper'.
To 'harden' your system even more you can run 'Bastille'.
For testing the security of a remote computer learn all
about Nmap.

Finally, a quick way to test the security of your
distro is to visit this site for a free system check.
--------------------------------------------------------------------
Note to moderator(s): edit at will - in the end I thought this was the best way to submit this post, edit the links and avoid undue stress.