Change the Default Table Prefix of your Joomla database

Changing the default table prefix will stop the majority of attacks against your database. You can use the DB Admin component in order to do this. Although it is originally designed for Joomla 1.0.x, it works on Joomla 1.5 too.

 Step 1. Install the component and go to Components > DB Admin.

 Step 2. Using the intuitive interface, change the default "jos_" prefix of your Joomla 1.5 tables to a different value.

 Step 3. Modify the configuration.php file in your main Joomla folder. In it locate the following line:

var $dbprefix = 'jos_';

You will have to edit it to correspond to the new table prefix you have set. For example, if you have changed the table prefix to "smth_" the line in the configuration.php file should look like this:

var $dbprefix = 'smth_';

The default table prefix of your Joomla database is now changed. This should block the majority of attacks against your database.