Use the following code on your .htaccess file to prevent hackers from using the PHP GLOBALS and _REQUEST variables to inject any malicious scripts into your website to gain access to your WordPress admin area.
# BEGIN Protect Against Script Injections
Options +FollowSymLinks
RewriteEngine On
RewriteCond %{QUERY_STRING} ((left pointy bracket)|%3C).*script.*((right pointy bracket)|%3E) [NC,OR]
RewriteCond %{QUERY_STRING} GLOBALS(=|[|%[0-9A-Z]{0,2}) [OR]
RewriteCond %{QUERY_STRING} _REQUEST(=|[|%[0-9A-Z]{0,2})
RewriteRule ^(.*)$ index.php [F,L]
# END Protect Against Script Injections
