Automating Malware Analysis Part 2

I've heard rumors that the latest issue of Hakin9 is on stands now. This issue contains the second part of my article on automating malware analysis and adds memory analysis and sandnet capabilities to the analysis script.

In the script, memory analysis is performed by suspending the virtual machine (as opposed to shutting it down as the first script did). When a VMWare VM is suspended, the memory for the machine is dumped into a file which can then be analyzed. This file is analyzed using the Volatility Framework.

Volatility is an amazing tool which can extract information from Windows XP SP2 & SP3 memory images. The analysis script in the article uses Volatility to extract the process list, network connections, list of loaded DLLs and list of loaded modules of the VM memory. However, Volatility can do so much more that I highly recommend extended what is in the article.

In addition to memory analysis, the article adds sandnet capabilities to the script. In the original script, the VM was set up in host-only networking mode which prevented the malware from communicating to anything over the network. This really limited the analyst in what they could see. For example, if the malware wanted to download additional files from a web server, the analyst would never see it.

To allow network connectivity, and still keep the network the analyst was on safe from infection, the script uses a tool set called InetSim to create a fake Internet for the malware to interact with. InetSim loads a number of localized servers (DNS, HTTP, etc) and logs any data sent to it. Now, when malware attempts to connect to a web server it will be able to and the analyst will see what it is attempted to download. I blogged about InetSim and how to install InetSim back in February.

I hope everyone enjoys the article. Please send me any feedback on the article or enhancements to the script. It does not appear that Hakin9 has posted the code listing for it yet, but as soon as they do I'll link to it from here. Of course, feel free to contact me to get the code if you want.

Automating Malware Analysis article

In the latest Hakin9 issue (3/2009), I have an article on automating malware analysis. The article discusses how one can set up their own malware analysis automation system using VMWare, some analysis tools and two scripts. The article uses a Linux system as the base system and a Windows XP Pro as the guest/analysis OS, but I don't see why one couldn't use Cygwin on Windows for a base system with a few tweaks.

The scripts I created for the article are meant to be used as a base for your own automated analysis system - they are meant to be expanded upon. I encourage others to add other tools and capabilities to the scripts and share them here on the blog. The scripts used are available on Hakin9's site. However, if anyone wants the actual files let me know and I'll send them out.

I should point out that the system and scripts in this article assume you are in VMWare's host-only network mode. This is to prevent malware from accidentally infecting other systems on your network, the Internet, etc. However, since the system is set up host-only mode your malware will not be able to communicate with any hosts. The only network traffic you will see are DNS requests and probes to systems that go unanswered.

I encourage others to implement this into their automation system using software such as Truman, fakedns, or InetSim to create a virtual network. Don't want to take the time? Then you'll have to wait for the next issue of Hakin9 where I have part 2 to this article and show how to set this up (along with some other cool things).

I'd love to hear any feedback on the scripts, tools, or the article...including anything you use to expand upon it.

Internal Laughs

Most malware that I look at these days is packed, sometimes double-packed, in order to hide whats inside. When they aren't packed, many times the strings inside the binary are encoded or encrypted so a strings program can't see what is going on.

Sometimes, however, if you wish REALLY hard and REALLY believe, you come across a gem like the one I looked at last night. I was notified of a piece of malware sitting on a server from one of my many sources I have. After downloading it, one of the first things I did was run the Sysinternals strings* utility against it. I found some interesting things:

C:\Documents and Settings\James\Desktop\MSN Pass Stealer\Stub\Project1.vbp

Hello AV Companies, Please Call Me

Hello AV Companies, Please Call Me Win32.MSNPassSteal.VB Thank You!

Its so nice to see things like this at times. While I'm pretty sure James didn't write this particular piece of malware, he probably did modify the source (MSN password stealer source code is easy to find) and compiled it.

James - if you are reading this let me give you some advice. First, learn how to use your compiler and how to turn off the debugging features that are turned on by default. Second, AV companies are not going to name your malware something you want. None of them did.

And finally, if you are going to use a user ID to post the results under, don't make it unique. Our intrepid fellow put the website the stolen credentials would post to as well as the user ID to use. While I'm not 100% sure it's James' ID (whh is why I didn't show it), it is very unique and can be traced back to a single user.

Then again, James, don't follow my advice. It'll be easier to catch you that way. :)


* Even though I do 99% of my static analysis on Linux, I prefer the Sysinternals strings program because it can grab unicode strings and to my knowledge the Linux strings cannot. It works just great under wine. If anyone knows of a Linux strings program that can grab unicode strings, let me know.

The Universal Language of Computer Viruses

I do alot of malware research in my spare time. As pointed out by one of the latest posts on spylogic.net, I'm somewhat known for it in the area (although legendary may be pushing it a little.) :)
However, it occurred to me last night how much malware has tied me into other people. For example, last night I was out getting a new phone. I was talking to the guy selling me the phone and ended up telling him I worked in computer security. He asked if I did anything with computer viruses. (I should have seen where this was going.)

When I told him I did, he said that he was using LimeWire to download a new Kevin Bacon movie (oops), but inadvertently installed a virus instead. He said his computer kept flashing on and off making it almost inoperable. I gave him a few suggestions and my card and told him that if those didn't work to email me.

I just think its funny how computer viruses have become a tying factor for me to others. :)

BTW, I'm going to try something new. For the next 30 days, I will be posting an entry every day. Don't expect these to be earth-shattering, but it will at least get me in the habit to keep this thing alive, which is what I intended it to be.