We still have some clients on Joomla version 1.5. By default Joomla creates the following Meta tag when it renders the web page:
<meta name="generator" content="Joomla! 1.5 - Open Source Content Management" />
This meta tag tells tools that crawl websites that the website was created with Joomla version 1.5. This is great for tools that aggregate data to assess the market penetration of different CMS tools like Joomla. But this also tells hackers what tool and version you’ve used to create your website. If there are vulnerabilities for that version of the CMS you’ve made it that much easier for them to hack your website.
For those that are comfortable with editing code files, just comment out the following line with double forward slashes in the /libraries/joomla/document/html/renderer/head.php file:
// $strHtml .= $tab.'<meta name="generator" content="'.$document->getGenerator().'" />'.$lnEnd;