Categories
WordPress

WordPress Security

And the Chamber of Secrets.

Improve system security at the WordPress level:

  • Secure the server
  • Grant folder 755 and files 644 permission
  • Update frequently
  • Install few plugins as possible
  • Report any suspicious activity in your account to your hosting provider
  • Use the build-in tool “Site Health”
  • Remove unused themes
  • Install SSL certificate
  • Make use of an Editor user and use Admin only in need
  • Disable built-in dashbaord theme editor- add the directive to wp-config.php file:
define( 'DISALLOW_FILE_EDIT', true );

Disable directory browsing, prevent access to important files and directories, and XSS attacks protection- add the directives to the .htaccess file:

Options -Indexes

<FilesMatch "^.*(xmlrpc.php|error_log|wp-config\.php|php.ini|\.[hH][tT][aApP].*)$">
Order deny,allow
Deny from all
</FilesMatch>

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^wp-admin/includes/ - [F,L]
RewriteRule !^wp-includes/ - [S=3]
# Comment the following directive if multisite
RewriteRule ^wp-includes/[^/]+\.php$ - [F,L] 
RewriteRule ^wp-includes/js/tinymce/langs/.+\.php - [F,L]
RewriteRule ^wp-includes/theme-compat/ - [F,L]
</IfModule>

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]
RewriteCond %{QUERY_STRING} [a-zA-Z0-9_]=http:// [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]
RewriteCond %{QUERY_STRING} (sp_executesql) [NC]
RewriteRule ^(.*)$ - [F,L]

Disable PHP execution in the uploads directory- create inside a .htaccess file with the content:

<Files "*.php">
Order Deny,Allow
Deny from All
</Files>

Hide the WordPress version and login errors- add to functions.php file in the child theme:

add_filter( 'the_generator', '__return_false' );
add_filter( 'login_errors', create_function( '$a', "return 'Invalid Input';" ) );

Scan frequently the code in the WordPress directory and database for malwares detection and delete unused items, create full backup before each modification, consider reinstalling WordPress (core files, themes and plugins) from the Dashboard. Make use of the recently modified files command:

find ./ -type f -mtime -15

Remove the Mobile Spam Popup malware- delete the wp-tmp.php, wp-vcd.php, wp-feed.php files from wp-includes directory and delete the code which is creating them from the themes’ functions.php.

Remove the Japanese Keyword Hack malware- clean the malicious code from .htaccess, wp-config.php, sitemap.xml files and uploads directory.

As you probably have noticed- many WordPress malwares were not created to shut down the website, but rather to use its infrastructure and create clients traffic to purchase products on a third-party site, usually advertising prohibited health and wellness products.

Leave a Reply

Your email address will not be published. Required fields are marked *