How to secure Joomla and prevent being hacked?

Question

I know securing any website is a very tough and broad topic to be discussed upon but i want to relate this question to my specific website which i've been working on. It was coded in php by some other programmer around 2007 and i am responsible for it's management. My problem is it's being hacked time and again. Please help me

Joomla version 1.5.18(With Virtuemart)

Answer 1

Well for starters, you're using Joomla 1.5 which is old and less secure. Upgrade your site to Joomla 2.5 or 3.1 and then read the following, which is a question I answered a while back regarding what could be done to help prevent a Joomla attack:

Joomla! 2.5.4 Hacked: Having trouble with diagnosis