IP Restriction is a plugin that can set the ip access restriction on Joomla sites. When the plugin is enabled the offline page will appear.It is an easy to use plugin.Download free IP Restriction from below link.
Demo:http://extensions.joomla.org/extensions/access-a-security/site-access/login-restriction/20635
Download:
http://linkzquickz.com/908/IP_Restriction.zip
VTScan:
https://www.virustotal.com/en/file/2081cb6c9cb6ead96ab9a587c122df4cdbb285e812510a25c33fac6ccf759b76/analysis/1396436253/