It’s very important to change default admin url in magento to save your website from hackers. For this you need to do little bit changes in your site.
1. Go to app/etc folder of your magento website and open local.xml
<admin> <routers> <adminhtml> <args> <frontName><![CDATA[admin]]></frontName> </args> </adminhtml> </routers> </admin>
Instead of admin Write your new url (e.g: magAdmin).
2. Now go to your system cahce which located under var folder. Rename or delete the Cache folder.Clear all session. Now It’s done.
Visit the site admin by typing the new admin path.DOWNLOAD SOLUTION HERE