Threat Level: green Handler on Duty: Xavier Mertens

SANS ISC: Is This Chinese Registrar Really Trying to XSS Me? - SANS Internet Storm Center SANS ISC InfoSec Forums


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Is This Chinese Registrar Really Trying to XSS Me?

One of the emails that came through on our handlers list pointed out some interesting behavior.  When querying a domain (a sample in this case is shineecs.com), the registrar at the end of the response would include an HTML script tag.  See output below:

 

$ whois shineecs.com
 
Whois Server Version 2.0
 
Domain names in the .com and .net domains can now be registered
with many different competing registrars. Go to http://www.internic.net
for detailed information.
 
   Domain Name: SHINEECS.COM
   Registrar: XIN NET TECHNOLOGY CORPORATION
   Whois Server: whois.paycenter.com.cn
   Referral URL: http://www.xinnet.com
   Name Server: NS17.XINCACHE.COM
   Name Server: NS18.XINCACHE.COM
   Status: ok
   Updated Date: 30-jul-2012
   Creation Date: 07-apr-2009
   Expiration Date: 07-apr-2014
 
>>> Last update of whois database: Mon, 11 Feb 2013 16:55:40 UTC <<<
 
[SNIPPED LAWYERESE]
 
Domain Name      : shineecs.com
PunnyCode        : shineecs.com
Creation Date    : 2009-04-07 14:26:58
Updated Date     : 2011-06-27 16:33:59
Expiration Date  : 2014-04-07 14:24:29
 
[SNIPPED] 
 
Billing Contact:
  Name           : shineecs
  Organization   : shineecs
  Address        : XXXXX
  City           : hangzhoushi
  Province/State : zhejiangsheng
  Country        : china
  Postal Code    : XXXX
  Phone Number   :
  Fax            : XXX
  Email          : XXXX@shineecs.com
<script src="http://img2.xinnet.com/d/js/acmsd/thea178.js"></script>&nbsp;

When manually fetching that script, all that was retrieved is: document.write(""), so nothing is modified at this instant in time.  The domain in question resolves to an IP that has been implicated in a small number of instances of malware connected to some worm activity, but nothing deeply out of the ordinary.  The same is true for the IP connected to the registrar.  So why is this happening?  The registrar is doing this as a lazy way to do some analytics they find useful, so not malicious in this case.

What is fun, however, is that when I run a WHOIS via the various web tools, most all of them process this HTML tag as HTML instead of text, which means this would be a successful XSS vector if you could maliciously modify a WHOIS record.  

In this case, the registrar adds that script tag, not the registrant.  That said, if a registrar doesn't properly validate the information put in those fields, evil may ensue (the registrar I use does).  Or worse, if the registrar themselves are a bad player, they can do whatever they want.  In this case, an innocous issue, but another episode in the ongoing saga of web applications.  If you get input from a third-party source, make sure to scrub it to ensure that "bad things don't happen" like XSS.  

--
John Bambenek
bambenek \at\ gmail /dot/ com
Bambenek Consulting

John

248 Posts
ISC Handler
This is an interesting scenario with regards to XSS... If the owners of shineecs.com added this JS src link to the end of their email address and it populated into the WHOIS info then the Registrar itself has an XSS flaw as it is not output encoding/escaping the user supplied data. If, however, the registrar itself adding in this JS code, then as you highlighted, other web-based WHOIS sites are perhaps vulnerable to XSS as they are not output encoding the same data before showing it to end users.

In either case, this is an XSS vuln for these sites, but for you it is a potential drive-by-download most likely leading to some type of exploit kit.

As far as that remote link - yes, the thea178.js file is empty, but you thea177.js still exists :) I replaced http with hxxp -

document.write("<img src='hxxp://img2.xinnet.com/d/file/20121204/b0bb615fafed28ecff7994fb6ad68d92.jpg' border=0 width='116' height='118' alt='.ac.cn英文域名价格'>");

looking at a bunch of files thea176.js, thea179.js, thea180.js, it looks like this might be some type of banner ad campaign. Perhaps this is a guerilla method of injecting banner ads in remote WHOIS sites for revenue/clickstreams.
John
7 Posts Posts
This was a topic on a few lists a month ago about this same registrar. They apparently were using this as a "branding" campaign on their WHOIS records. So, not malicious, but probably obnoxious use of registrar records. Won't take long for malicious use though.
John

248 Posts Posts
ISC Handler
ARIN, et al, take note and validate input...
hacks4pancakes

48 Posts Posts
> If you get input from a third-party source, make sure to scrub it
Don't scrub it. Just encode it correctly. I.e. don't treat text as if it is html, but encode it to make it html. A piece of text won't become html by scrubbing it. You will only dig a deeper hole for yourself.
hacks4pancakes
3 Posts Posts
seems easy way to me to know not only if someone is suddenly interested in your domain, but who and maybe even a little about them if they were particularly careless
hacks4pancakes
1 Posts Posts
Did anyone see that shineecs is an anagram for chinese?
Anonymous
Posts
While I'm here, I'd like to re-iterate once again, that if IANA and ICANN enforced the rules on registrars, we wouldn't see as many fake domains out there. We need accountability. Every domain owner should be verified by phone, email and snail mail. Invalid WHOIS gets the domain deleted, registrar registers too many deleted domains, and the registrar loses accreditation.
Anonymous
Posts
@JoeBlow: it's not an anagram for chinese, it doesn't even hold the same number of characters. It could however be an anagram for chineses. ;o)
AlfredP

5 Posts Posts

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