Saturday, February 14, 2009

Opening Microsoft Compressed HTML Help (.chm) files

I have a few e-books formatted in Microsoft's Compress HTML Help format. To open these files, I had to install a viewer called xchm. To install it in Ubuntu, I opened a terminal shell and typed:

sudo apt-get install xchm

However, the installer did not associate .chm files with the xchm program in GNOME. To fix this, I right-clicked on a .chm file and selected "Properties". I then selected the "Open with" tab and chose xchm from the list of applications.

Friday, February 13, 2009

What anti-virus?

One cool thing about being a Ubuntu user the last four years is the fact that I do not need to install an anti-virus program into my computer. This only goes to show that linux is superior in design to Windoze. This saves me money (don't need to buy) and time (computer works faster). :)

Sunday, February 8, 2009

Installing OpenVAS 1.0.x on Ubuntu Linux...

OpenVAS (URL is an open source and fully GPL'ed fork of the now closed source Nessus security scanner. I will not go into the history of Nessus and why OpenVAS is a fork of that source code but will focus more on how I installed OpenVAS on my favorite Linux distro Ubuntu.

If you go to the OpenVAS site, they only have .rpm (aka RedHat) packages and can't be used on a Debian based distro like Ubuntu. Also, as a side note, if you want to do something else with OpenVAS which I am not covering, remember that you should best follow only the Ubuntu specific instructions and when that is not possible, for the Debian Etch instructions as Ubuntu uses the "Etch" branch of Debian.

The instructions below are for use with OpenVAS v1.x and not the new beta 2.0 (will write another article later when it gets out of beta).

Firstly, you will need to add the following repositories into aptitude by editing /etc/apt/sources.list and adding the following line into the sources.list file:

deb etch openvas

You then update your Ubuntu repositories by issuing the "apt-get update" command.

You then need to download the following source codes from the OpenVAS website. Which you can find at URL

They are:

openvas-libraries 1.0.2 (not needed, a .deb installer is available in the repository)
openvas-libnasl 1.0.1
openvas-server 1.0.2
openvas-plugins 1.0.4 (if there is a newer version > 1.0.4, download that instead)

Create a sub-directory in your home directory called "~/openvas1" and move all the .tar.gz source code files into this folder.

Then, you need to install certain libraries which OpenVAS uses prior to compiling the source codes you've downloaded by issuing the command:

apt-get install openvas-client libopenvas1 libopenvas1-dev libgpgme11 libgpgme11-dev bison build-essential

! in Ubuntu 8.10, prior to issuing the above command, you will need to install
! some libraries which are missing in Ubuntu 8.10.
! Download the following .deb (libgnutls13 and libopencdk10) files from the
! hardy packages (they'll work in Ubuntu 8.10)
! You can install the two .deb files by issuing the command:
! dpkg -i libgnutls13_2.0.4-1ubuntu2.1_i386.deb
! dpkg -i libopencdk10_0.6.6-1ubuntu1_i386.deb

You will then need to open the three source code files, untar them and compile them. You can do this for all three packages by typing in:

tar zxvf [filename of .tar.gz file]
cd [sub-folder of same name as .tar.gz file]
make install
cd ..

You will need to do the above with all three files, mainly:


in the above order.

You will then need to let your linux system know about the new libraries you have just compiled before the can be used by typing in:

ldconfig -v

You then need to copy the file openvas-services from the server source code folder into the /var/lib/openvas directory by issuing the following command in a bash shell:

mkdir /var/lib/openvas
cp ~/openvas1/openvas-server-1.0.2/openvas-services /var/lib/openvas/

For the first time use of OpenVAS, you will need to create a new cert and add in the first user that can login into the OpenVAS server by running both:


To start OpenVAS, activate the server by typing in:

openvasd -D &

And running the OpenVAS client by typing:


If all works well, when you run openvasd, you will see it attempt to load in all the plug-ins and in the openvas-client, connect to the openvas server.

Feel free to comment!

Note: Tested on Ubuntu 7.10, 8.04 and 8.10, and I assume you are doing all this with root access and am running the kernel in i386 (32-bit) mode.

Simple way to create an ISO image of your disc in Ubuntu...

Go to Terminal:

sudo umount /dev/cdrom
dd if=/dev/cdrom of=filename.iso bs=1024

To verify your ISO file is good:

md5sum /dev/cdrom
md5sum filename.iso

Both instances should produce the same md5 hash. :)

Note: "filename.iso" is only an example filename, feel free to use any name you want.

Sunday, February 1, 2009

Making the Firefox browser special

Let's face it, a web browser, is a web browser, is a web browser. Every operating system has at least two web browsers that users can choose to use. The difference between most browsers with Firefox is the fact that Firefox has add-ons which basically extends the functionality of the browser. I am sure that this is nothing new to most seasonal Ubuntu users, but most users new to Firefox do not realise that they can expand the functionality. This blog shows users (not in the know) how to find and add these add-ons and what are my favourite personal add-ons which you may or may not find useful.

Adding the add-ons

Launch Firefox and go to Tools -> Add-ons and the "Add-ons" windows will appear. You then go to the "Get Add-ons" tab and you can then find any and every add-on that was ever made for Firefox that Mozilla has tested and deemed safe for users to use. There are sites that offer the add-ons directly. However, getting them directly from Mozilla is a safe bet as they have been tested to work correctly "as advertised".

The best way to know what add-ons you want is to simply use the browser and ask yourself what improvements you would like to see to Firefox. Once you know what you want, simply figure out what keyword would best describe the feature you want and query in the "Get Add-ons" tab. The query result will display all add-ons that fit the search query and will then display a short description of what the add-on does. If the description fits what you want, you are then given the opportunity to install the add-on. You can also check the "Extension" tab to see what add-ons you have installed. You can also configure the behaviour of the extension to better fit your needs.

Extension/Add-ons that I use

The list below are the extensions that I use. It is in no way an endorsement to the following add-on authors but it is a list of add-ons that I use that I find useful and convenient. They are:

  • Ad Block Plus
  • Download Statusbar
  • PageZoom
  • QuickJava
  • Server Spy
  • ShowIP
  • SwitchProxy Tool

To know what these tools do, may I suggest you query them in the "Get Add-ons" tab and have a read yourself.