How I secured my WordPress site

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I recently came across malware in my WordPress installation even though I am running the latest version of WordPress and not running any other plugin apart from JetPack. I tried removing the malware and updating all the WordPress files only to get infected again a few days after. So Far these steps have mitigated the malware from infecting  and/or penetrating my site.

.htaccess conditions

I added these rules to my .htaccess file. This will append or replace the existing rules of WordPress as well as the WordFence Plugin if you use it,

# BEGIN WordPress
<IfModule mod_rewrite.c>
	RewriteEngine On
	RewriteBase /
	RewriteRule ^index\.php$ - [L]
	RewriteCond %{REQUEST_FILENAME} !-f
	RewriteCond %{REQUEST_FILENAME} !-d
	RewriteRule . /index.php [L]

	# protect wp-admin and wp-incluide
	RewriteRule ^wp-admin/includes/ - [F,L]
	RewriteRule !^wp-includes/ - [S=3]
	RewriteRule ^wp-includes/[^/]+\.php$ - [F,L]
	RewriteRule ^wp-includes/js/tinymce/langs/.+\.php - [F,L]
	RewriteRule ^wp-includes/theme-compat/ - [F,L]

	# Block suspicious request methods
	RewriteCond %{REQUEST_METHOD} ^(HEAD|TRACE|DELETE|TRACK|DEBUG) [NC]
	RewriteRule ^(.*)$ - [F,L]

	# Block WP timthumb hack
	RewriteCond %{REQUEST_URI} (timthumb\.php|phpthumb\.php|thumb\.php|thumbs\.php) [NC]
	RewriteRule . - [S=1]

	# Block suspicious user agents and requests
	RewriteCond %{HTTP_USER_AGENT} (libwww-perl|wget|python|nikto|curl|scan|java|winhttp|clshttp|loader) [NC,OR]
	RewriteCond %{HTTP_USER_AGENT} (<|>|'|%0A|%0D|%27|%3C|%3E|%00) [NC,OR]
	RewriteCond %{HTTP_USER_AGENT} (;|<|>|'|"|\)|\(|%0A|%0D|%22|%27|%28|%3C|%3E|%00).*(libwww-perl|wget|python|nikto|curl|scan|java|winhttp|HTTrack|clshttp|archiver|loader|email|harvest|extract|grab|miner) [NC,OR]
	RewriteCond %{THE_REQUEST} \?\ HTTP/ [NC,OR]
	RewriteCond %{THE_REQUEST} \/\*\ HTTP/ [NC,OR]
	RewriteCond %{THE_REQUEST} etc/passwd [NC,OR]
	RewriteCond %{THE_REQUEST} cgi-bin [NC,OR]
	RewriteCond %{THE_REQUEST} (%0A|%0D) [NC,OR]

	# Block MySQL injections, RFI, base64, etc.
	RewriteCond %{QUERY_STRING} [a-zA-Z0-9_]=http:// [OR]
	RewriteCond %{QUERY_STRING} [a-zA-Z0-9_]=http%3A%2F%2F [OR]
	RewriteCond %{QUERY_STRING} [a-zA-Z0-9_]=(\.\.//?)+ [OR]
	RewriteCond %{QUERY_STRING} [a-zA-Z0-9_]=/([a-z0-9_.]//?)+ [NC,OR]
	RewriteCond %{QUERY_STRING} \=PHP[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12} [NC,OR]
	RewriteCond %{QUERY_STRING} (\.\./|\.\.) [OR]
	RewriteCond %{QUERY_STRING} ftp\: [NC,OR]
	RewriteCond %{QUERY_STRING} http\: [NC,OR]
	RewriteCond %{QUERY_STRING} https\: [NC,OR]
	RewriteCond %{QUERY_STRING} \=\|w\| [NC,OR]
	RewriteCond %{QUERY_STRING} ^(.*)/self/(.*)$ [NC,OR]
	RewriteCond %{QUERY_STRING} ^(.*)cPath=http://(.*)$ [NC,OR]
	RewriteCond %{QUERY_STRING} (\<|%3C).*script.*(\>|%3E) [NC,OR]
	RewriteCond %{QUERY_STRING} (<|%3C)([^s]*s)+cript.*(>|%3E) [NC,OR]
	RewriteCond %{QUERY_STRING} (\<|%3C).*iframe.*(\>|%3E) [NC,OR]
	RewriteCond %{QUERY_STRING} (<|%3C)([^i]*i)+frame.*(>|%3E) [NC,OR]
	RewriteCond %{QUERY_STRING} base64_encode.*\(.*\) [NC,OR]
	RewriteCond %{QUERY_STRING} base64_(en|de)code[^(]*\([^)]*\) [NC,OR]
	RewriteCond %{QUERY_STRING} GLOBALS(=|\[|\%[0-9A-Z]{0,2}) [OR]
	RewriteCond %{QUERY_STRING} _REQUEST(=|\[|\%[0-9A-Z]{0,2}) [OR]
	RewriteCond %{QUERY_STRING} ^.*(\[|\]|\(|\)|<|>).* [NC,OR]
	RewriteCond %{QUERY_STRING} (NULL|OUTFILE|LOAD_FILE) [OR]
	RewriteCond %{QUERY_STRING} (\./|\../|\.../)+(motd|etc|bin) [NC,OR]
	RewriteCond %{QUERY_STRING} (localhost|loopback|127\.0\.0\.1) [NC,OR]
	RewriteCond %{QUERY_STRING} (<|>|'|%0A|%0D|%27|%3C|%3E|%00) [NC,OR]
	RewriteCond %{QUERY_STRING} concat[^\(]*\( [NC,OR]
	RewriteCond %{QUERY_STRING} union([^s]*s)+elect [NC,OR]
	RewriteCond %{QUERY_STRING} union([^a]*a)+ll([^s]*s)+elect [NC,OR]
	RewriteCond %{QUERY_STRING} (;|<|>|'|"|\)|%0A|%0D|%22|%27|%3C|%3E|%00).*(/\*|union|select|insert|drop|delete|update|cast|create|char|convert|alter|declare|order|script|set|md5|benchmark|encode) [NC,OR]

	# PHP-CGI Vulnerability
	RewriteCond %{QUERY_STRING} ^(%2d|\-)[^=]+$ [NC,OR]

	#proc/self/environ? no way!
	RewriteCond %{QUERY_STRING} proc\/self\/environ [NC,OR]

	RewriteCond %{QUERY_STRING} (sp_executesql) [NC]
	RewriteRule ^(.*)$ - [F,L]
</IfModule>

<files wp-config.php>
	order allow,deny
	deny from all
</files>
# END WordPress

# Wordfence WAF
<Files ".user.ini">
<IfModule mod_authz_core.c>
	Require all denied
</IfModule>
<IfModule !mod_authz_core.c>
	Order deny,allow
	Deny from all
</IfModule>
</Files>

# END Wordfence WAF

Installed WordFence and Really Simple SSL Plug-in

I installed WordFence to scan and replace WordPress core files. I only use the free version, though there is a premium version available with more automation features. I also installed a SSL certificate on my server and installed Really Simple SSL to force HTTPS on my main site.

Updated passwords and changed DB table prefix

If you haven’t already, I updated all database and user passwords in my current WordPress installation as well as changing the default database table prefix (wp_) to something obscure.

Set file and directory permissions

Set directories to 755 and files to 644. I simply run these commands via SSH

cd /home/user/domains/domain.com/public_html
find . -type d -exec chmod 0755 {} \;
find . -type f -exec chmod 0644 {} \;

Limit or disable access to XML-RPC

I use .htaccess to limit access to the xmlrpc.php file since I use the WordPress app. You can opt to simply deny access to the file all together if you don’t plan on using it.

# Block WordPress xmlrpc.php requests 
# Allow Jetpack IP's 
<Files xmlrpc.php>
	order deny,allow
	deny from all
	Allow from 192.0.64.0/18
	Satisfy All
</Files>

 

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