Joomla! 1.5 is now end-of-life and if your site is still running on Joomla 1.5.x or Joomla 1.x, unfortunately, there is a high chance that it can get compromised at any time. Securing your site before its too late is always a smart move. The security has always been an important issue for Joomla! developers and they continuously work to improve both the features and the security of Joomla CMS ( Content Management System )
Those sites which are found to be still running on outdated CMS often becomes target of hackers and malware; hence, CMS migration to latest version and fixing security loopholes is necessary.
Joomla! Upgrade or Joomla! Migration from Joomla! 1.5 to Joomla! 2.5/3.x is not always straightforward and requires attention to detail since the platform and underlying architecture has changed quite a bit.
I am Expert in Migrating Joomla 1.5 to Joomla 2.5/3.x alongwith all its major extensions such as