Posts Tagged ‘PHP-Shell’

Automated attacks since 12/2010 using compromised credentials / chain reaction

2011/01/12 3 comments

Is your browser giving you a content warning while accessing legitimate websites? You get a virus warning while reading your favorite online newspaper? Here is why:

In october 2010 a “feature” was disclosed that Filezilla caches credentials silently in a XML document. This feature was 0-day before and has been used since then by malware to collect user credentials. Today, there might be a collection of some million compromised records.

Since December 2010, compromised websites are upcoming which are an evidence for an automated mass hack. For this hack it doesnt matter which OS, service or application (cms, joomla) is installed as long as the access password wasn’t changed. So every content can be changed, even save-known, non-active pages like html.

The attack starts with the used protocol, in this example via FTP. The bot starts to retrieve every existing index.* file on server and includes an (hidden) iframe:

The files are then uploaded again, together with a PHP Shell and a blackhat-seo framework.

This server based in Ukraine seems to be a counter and decision server. Depending on the OS and used browser the client ist then redirected to a different server. Here a server in Austria:

The access is checked for a valid referer (you have to come from the counter server to get content). On a direkt access the php is empty. It strongly depends on the used browser, version and OS which content you reveive. (An up-to-date Firefox blocks the austrian domain immediately due to reports)

When the check is disabled/an older browser is used, and you are using Java you receive the following

<applet mayscript=’true’ archive=’jzdlgoazhzfvkli3.jar’ code=’a.class’><param name=’trigger’ value=’isie’><param name=’url’ valuetype=’ref’ value=’http:/’></applet><body id=’jpyvaq9′ name=’jpyvaq9′></body>

This Java code uses two different kinds of the sound/midi exploit to infect the client (this IP address is based in India).

Now see how “good” these two “old” java exploits are detected by up-to-date antivirus scanners, only 4 out of 47 detect the malware:……

Here is the link to the pastebin with the malicious code:

Here is the code deobfusicated:

You now can easily see the exploited vulnerabilites.

This seems to be the Phoenix Exploit Kit

The Phoenix Exploit Kit includes exploits for the following vulnerabilities:

Flash exploits

Adobe Flash Integer Overflow in AVM2 – CVE-2009-1869
Adobe Flash Integer Overflow in Flash Player CVE-2007-0071

PDF exploits

Adobe Reader CollectEmailInfo Vulnerability CVE-2007-5659
Adobe Reader Collab GetIcon Vulnerability CVE-2009-0927
Adobe Reader LibTiff Vulnerability CVE-2010-0188
Adobe Reader newPlayer Vulnerability CVE-2009-4324
Adobe Reader util.printf Vulnerability CVE-2008-2992

Internet Explorer Exploits

IE MDAC Vulnerability CVE-2006-0003
IE SnapShot Viewer ActiveX Vulnerability CVE-2008-2463
IE iepeers Vulnerability CVE-2010-0806

Java Exploits
JAVA HsbParser.getSoundBank Vulnerability CVE-2009-3867
Java Development Kit Vulnerability CVE-2008-5353


I was too slow to decrpyt the script to be able to download the files as the servers have been shutdown in between (half a day).

But these exploits will definately try to drop a (or more) trojan(s) then, search the compromised user account for saved passwords, and might also hook into the browsers to get credentials directly, which then will be submitted to a server, which will be used to compromise the next server. And it goes on and on…

As you can see, even a good virusscanner might allow the trojan to be run. So don’t feel save.

  1. Don’t use filezilla
  2. Never save credentials in the browser
  3. Don’t use Internet Explorer
  4. Keep your OS, Browser and third-party software (Adobe Flash, Java..) up-to-date
  5. Perodically change your passwords
  6. Use security browser plugins like adblockplus and noscript