While researching PlugX propagation with the use of Java exploits we stumbled upon one compromised site that hosted and pushed a malicious Java applet exploiting the CVE 2013-0422 vulnerability. The very malicious Java application was detected heuristically with generic verdict for that vulnerability and it would have been hardly possible to spot that particular site between tons of other places where various malicious Java applications were detected with that generic verdict. But it was a very specific search conducted back then and this site appeared in statistics among not so many search results. Well, to be honest it was a false positive in terms of search criteria, but in this case it was a lucky mistake.

The infectious website was an Internet resource named - minjok.com and it turned out to be a news site in Korean and English languages covering mostly political events around the Korean peninsula. We notified an editor of this site about the compromise and although he has not responded, the site got closed after a while.

This is how minjok.com is described at http://www.northkoreatech.org/the-north-korean-website-list/minjok-tongshin/:

Description of minjok.com

A new-ish Flash exploit has been on the loose for attacks around the web. This time, the attackers have compromised a caregiver site providing support for Tibetan refugee children and are spreading backdoors signed with Winnti stolen certificates delivered with Flash exploits - the compromised web site is the NGO "Tibetan Homes Foundation". Previously, FireEye identified similar "Lady Boyle" related malicious swf exploiting CVE-2013-0634. A notification has been sent to the contacts of the web site, but apparently the malicious footer.swf file is still hosted at the Foundation's web site, so please do not visit it just yet. Also, be sure to update your Flash player to the latest version.

This site certainly appears to be a classic example of a "watering hole" attack. F-Secure pointed out another Lady Boyle watering hole set up against a related Uyghur group, which has been targeted in tandem following the early March World Uyghur Congress. The delivered backdoors are shown to be signed with Winnti-stolen digital certificates in the F-Secure post, including the stolen MGAME certificate.

Here is an example of those same stolen certs reused for the backdoors in the Tibetan Homes Foundation incident. We see both the MGAME cert and the ShenZehn certs signing the backdoors, here are screenshots of the latter:

Our products detect the Flash exploit+payload as Exploit.SWF.CVE-2013-0634.a. Here is a heatmap of our worldwide detections. Note that not all of these detections are Lady Boyle related, I estimate that at least a third of them are:

Other sites hosting the Lady Boyle swf exploit over the past couple of months have included "tibetangeeks.com", who recently cleaned up their site and posted a cooperative plea to their attackers, and "vot.org" or the "Voice of Tibet" which is also cleaned up. Currently cleaned up but previously serving "Exploit.SWF.CVE-2013-0634.a" were Uyghur related sites "istiqlaltv.com" and "maarip.org", with the same "LadyBoyle" swf path as the Tibetan Homes Foundation, i.e.:
hxxp://maarip.org/uyghur/footer(.)swf

So, what we have is an active watering hole campaign implementing a fairly new Flash exploit and abusing digital certificates that were stolen as a part of the ongoing Winnti targeted attack campaigns on game developers and publishers.

Related md5:
BD9FD3E199C3DAB16CF8C9134E06FE12
215CEC7261D70A5913E79CD11EBC9ECC
12181311E049EB9F1B909EABFDB55427

Earlier today, the Laboratory of Cryptography and System Security (CrySyS Lab), together with the Hungarian National Security Authority (NBF), published details on a high profile targeted attack against Hungary. The details about the exact targets are not known and the incident remains classified.

Considering the implications of such an attack, Kaspersky Lab’s Global Research & Analysis Team performed a technical analysis of the campaign and related malware samples.

You can read our short FAQ below and you can download our technical analysis paper linked at the end of the blogpost.

Recently, we came across web malware that – instead of injecting an iframe pointing to a fixed existing address – generates a pseudo-random domain name, depending on the current date. This approach is not new and is widely used by botnets in C&C domain name generation, yet it's not very common for the web malware we’ve seen so far.

After deobfuscation, we can see that the iframe redirecting to the malicious URL with generated domain name is appended to the HTML file. All URLs consist of 16 pseudo-random letters, belonging to the ru domain and execute PHP script on the server side with the sid=botnet2 as argument:

A few days ago, I blogged about a PHP/JS malware targeting the osCommerce platform, which used an interesting new technique to obfuscate the malicious code. It so happens, that today I came across even more advanced sample of a PHP infector, also in the context of a vulnerable e-commerce solution.

When I came to work today, my colleague from our Polish office asked me to help him with finding malware which was affecting his friend's online store. The HTML page, viewed with the browser, contained a link to a jquery.js script in some randomly generated cx.cc domain, although there was no sign of this link in the source files on the server. Reaching a verdict was simple - this piece of code was being added dynamically, by some infected PHP script.

We looked into all of PHP files stored on the server and got a bit confused - there was nothing really suspicious at first glance. But having in mind the div_colors malware, I started to study the code line by line. What at last attracted my attention was a small function at the beginning of one of the core PHP files.

New techniques for obfuscating malicious code on websites are a good way to mislead both users and protection software alike. Recently, I came across an interesting attack against the osCommerce online shopping platform in which malicious script was injected into PHP files by exploiting a Remote File Inclusion vulnerability in osCommerce software.

This PHP script works as an infector and is used to add the following code just after specified tags in HTML files and at the top of JavaScript files:

At first glance, this code doesn't look as suspicious as it usually does - there is nothing that stands out: no <iframe> tag, no unescape() function, nor is there an eval(). Instead, we just have a function which seems somehow related to colours displayed on the web page and an array filled with values pretending to be a hex representation of these colours. Unwary users could overlook this code assuming that it's legitimate and belongs to the page, but if we follow it, we can see what it really does. The code takes the values from the array, converts them in some way and builds an ASCII string, so it can then use either the document.write or document.createElement method to append text to the web page source code. It the latter case, the created element has a type of text/javascript.

Now does it look suspicious enough to you? :)

If the second parameter of the div_pick_colours() function is specified, the function returns:

in which the last value always differs and depends on the current date and time. Otherwise, it returns the same URL but without <script> tags. The given address is not active anymore, so we couldn't tell what kind of threat it used to lead to.

Kaspersky Lab detects this malware as Trojan-Downloader.PHP.JScript.a and Trojan.JS.Redirector.px. According to Virus Total, at the time of writing only one other AV vendor was able to detect the PHP part of this malware. For script injected into JS and HTML the ratio was as low as 20%.

How to secure your website from being infected with such malware and what to do in case of infection?

Two most important things are backup copies and regular scanning of all the files on the server. If you are using osCommerce or any other e-Commerce solution, you should always check for the software updates and install them as soon as they're being released. Sometimes the time between disclosing a vulnerability and publishing patch can be shamefully long, so maybe it's worth considering to reject some buggy features and delete vulnerable files from the server. Setting up password on the root directory is also a very good idea, as it prevent malware from modifying core files.

The Democratic Party of Hong Kong's website was compromised and malware uploaded to the web server. Interestingly, the server was distributing malicious flash and spyware nearly identical to the compromised UK Amnesty International servers at the beginning of this month. The server is being cleaned up.

The english version of the website did not include injected iframe links pointing to the exploit.html page, which in turn delivers three different version-appropriate malicious variants of flash detected by Kaspersky as "Exploit.SWF.CVE-2011-0611". The malicious flash was 0day at the beginning of this month, and will be effective on unpatched systems.

    There have been several reports about malware hosted on Mozilla and Google code servers. Now we also found malware hosted on My Opera community servers. The screenshot below shows an example of this:

It’s a PHP based IRC botnet. Analyzing the code I found some evidences that it comes from Brazil.

We can see that criminals appreciate and actively use any and all available free web space. Based on the statistics from one of our proactive web crawlers, I took a look at which free web hosts are most popular among criminals for uploading and spreading malware. The following graph shows the top 10 free web hosts used by criminals during the last 8 months:

Fileave is a really well known server for hosting tons of different kinds of malware. I noticed that some secure DNS providers block access to the domains listed above and show an alert message stating that these sites are known sources of phishing and malware. So, what does that tell us? The usual - when you browse the internet always check links before clicking, and if the domain is suspicious, don't. Just don't click. And if you’re owner of a web site, make sure to secure your server properly to prevent the criminals from compromising it easily.

In recent spam mails we have often noticed links to *.html files with random names. Another trend is that the cybercriminals do not even bother to register domains for their dirty deeds, but simply plant their malicious code on compromised hosts. "Simply?" one may ask, and sadly the answer seems to be "yes" based on our observations.

For example, we have collected some hundred mails of a certain type promoting online software shops - a small portion is shown in the animated gif image below.

All of the samples stick out by virtue of the fact that they contain colored text/links which point to compromised legitimate websites. The links also show that the locations of the files are directly on the root URLs and not in a subfolder of some vulnerable application as we usually see.

We can assume that the intruders have ‘write’ access, at least to the www root of the involved sites - a very worrying fact. We have also confirmed that in many cases not only were the abovementioned spam links stored on the victim’s servers, but additionally, malicious iframes or javascript snippets were injected into the main content of the sites.

Another sample reaching us today just confirms that the cybercriminals are not sparing with the domains they abuse, and indeed seem to have a pool of unknown quantity at their disposal. The capture below shows a spam mail where each of the 12 links in the mail body points to a unique site. All of these sites also contain malicious code in their root which we detect as 'Trojan-Clicker.JS.Agent.*'

Please do not attempt to visit these links shown if you are not sure of what you are doing.

Looking up definitions for 'iframe' does indeed give results about "... a constraint of the H.264 codec specified by Apple to ensure ease of consumer video editing.". Such iframes do contain all necessary rendering information and serve as reference to construct other frames. But here we discuss the other kind of iframes - HTML tags. Iframes can have several attributes and we often encounter them when analysing malicious sites. They are often used in a hidden way to construct drive-by downloads of malware. To hide even more, simple encryption (also called 'obfuscation') is often used, web browsers decrypt that on the fly. Knowing that, we can search for interesting websites. For example doing a web search for "#64#6f#63#75#6d#65#6e#74#2e#77#72#69#74#65" (which decodes to 'document.write'), we instantly get 10,000+ results.

The first entry in our search results is a link to a torrent site where users discuss a malicious package. Ironically in between these search results we also noticed what seems to be an 'infected podcast' hosted at itunes.apple.com - which brings us back to the initial talk about iframes. The injected code contains an iframe redirecting to moshonken(dot)com, a host known for having spread exploits in the past. Currently that host appears to be not operational but malicious code trying to access it is still injected in many legitimate sites, as our search results showed. We detect this code as 'HEUR:Trojan.Script.Iframer' and have reported the problem via Apple's feedback form.