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Re: [LUG] Security

 

ian_nichols@xxxxxxx wrote:
> 
> Posted by "Ian Nichols" <ian_nichols@xxxxxxx>
> 
> This is my first excursion into the Linux world. I have just loaded
> Mandriva Powerpack 2008 onto an old(ish) Packard Bell. All appears to
> be working fine, albeit with a fairly steep learning curve. My
> concern is how do I load a security package. I have tried downloading
> AVG but it does not seem to have installed. Any   advice would be
> much appreciated. Words of single syllables please. Many thanks. -- 

Look at ClamAV if you want antivirus, there are some graphical
interfaces around for it.

There are almost no viruses in the wild for GNU/Linux systems, so most
people don't bother with antivirus. Benefit to risk ratio is simply not
worth it for most people.

I've seen a couple of boxes compromised due to running old server
software, and one with a password guessed. The server exploits were
automated, so worm like, but nothing like Windows desktop malware (i.e.
nothing coming in via web browsing (except the odd tracking cookie) or
reading email - even though it has been possible at times).

Most viruses are spread due to design issues with the operating systems
which have viruses (mainly old versions of MS Windows, and DOS, which
let users overwrite important system files, and executables, or which
allow executable content to be embedded or run automatically in various
file types, or macro languages that can do more than is useful....), or
conning users into running attachments (which usually requires a click
or two more for GNU/Linux - I don't think I've ever been sent a
GNU/Linux virus by email, except by security people going "look a
GNU/Linux virus, how unusual is that!").

Most problem malware that exists for GNU/Linux is server side, so if you
aren't running a web server, and don't offer services to the outside
world the risk is minuscule currently.

For the paranoid web surfer - the Firefox NoScripts plugin is excellent
and recommended (since it will help stop cross site scripting attacks
and such like) - but can be a bit confusing when it breaks web pages in
unexpected ways.

NoScripts
https://addons.mozilla.org/en-US/firefox/addon/722

It is generally better to secure the system than to try and enumerate
badness.

Essential reading...

http://www.ranum.com/security/computer_security/editorials/dumb/

So you might check if Mandriva has support, can use:

A) SELinux (system for ensuring application only do what they are
suppose to)

(I drew a blank on Mandrive specific SELinux resources)

B) tripwire or similar (tools that checks whether key files have
changed, kind of the opposite of antivirus, these fingerprinting tools
are run on a known good system, and then report deviations from
pristine, rather than trying to identify changes known to be bad and
ignoring the unknown changes, such as caused by new viruses).

Introduction here - there may be easier tools around! (I hope so).
http://www.linuxsecurity.com/content/view/117563/171/

C) fail2ban (or other system for disallowing login attempts for services
that are allowed - assuming you do provide SSH or some other inbound
services).

http://www.howtoforge.com/preventing-brute-force-attacks-with-fail2ban-on-mandriva2008.1
(Falko Timme - I know that name - he's good!)

D) There are also some graphical firewall products around. Probably
worth it for laptops, but for home users I'd say using a router with NAT
and only forward incoming stuff you want.

Not seen this one before myself - but sounds very Madriva specific.
http://wiki.mandriva.com/en/Interactive_Firewall

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