|By Cory Marchand||
|June 27, 2012 07:00 AM EDT||
Malware analysis can be a time consuming process, especially when dealing with a sample from skilled attackers with time and money on their side . There is no doubt that fully reversing malware and finding out how it works is the most effective way to learn how to defend against it, but most businesses don't have the time or the professional resources to do it.
There are ways in which you, a Computer Network Defender, can glean enough information from malware to be used in IDS and AV signature creation, DNS poisoning and blocking as well as sharing with the CND community. This can be accomplished in a cost effective manner (maybe even free) and in an efficient manner that can rival very long code based analysis. There are even cases where in depth knowledge of how to fully reverse the sample is not needed.
It should be noted that this is a low tech, high level mechanism for capturing indicators from malware. It should not be considered a substitute for fully analyzing malicious software, as sophisticated samples can defeat a lab environment similar to this quite easily. I will not be covering anything related to debugging the malware, that is outside of the intention of this "How-to".
Before we start, you will need to procure a few bits and pieces:
- Host machine with enough storage and memory to run at least 2 virtual machines concurrently, 4GB of ram and at least 30GB would be the minimum requirement.
- A virtualization platform, there are several on the market, some of them are free to use, VirtualBox and Xen to name a couple. I will be using VMWare Fusion for this demonstration.
- A copy of "REMNUX", a reverse-engineering malware linux distribution available at http://zeltser.com/remnux/.
- A licensed copy of MS Windows (this will be your victim host). I will be using WindowsXP for this demonstration.
- Free and open source tools for analysis of the Windows host (Putty, RegShot, Sysinternals, etc etc)
Setting Up the Victim Host Machine
Something to consider when setting up your victim host machine is system and software patches. Depending on what you are testing on your victim host, it may only affect a certain version of Windows, or possibly only to a certain patch level. Something I like to do is to "snapshot" my "victim" host machines through various patch stages, that way if I need to roll back, it's as easy as choosing a snapshot and "rolling back". This also applies to the types of software you install on your victim, snapshot your host with different versions of java, flash and adobe reader to be able to quickly select a vulnerable configuration. Consider outfitting your malware analysis lab setup with hosts that mimic your native operating environment. If you only utilize Windows 7 and do not allow Firefox on your network, then set up your victim machines to match that configuration.
Once you have finished patching your host, downloading and installing various types of software to aid in allowing successful exploitation you are going to setup a new network adapter, and set it for "host-only". This will keep your host from accidentally reaching the Internet once infected. It will also allow you to send the traffic to another machine to analyze what your victim is trying to do once successful exploitation has taken place.
- Set the IP on your victim host to a non-routable address, for instance 10.1.1.10.
- Set your router or gateway to be 10.1.1.1, this will the IP address of your REMNUX virtual machine.
Setting Up the REMNUX Host Machine
One of the main purposes for the REMNUX virtual machine in this demonstration is simply to act as a catch-all for network traffic originating from your now exploited victim host. REMNUX has many uses and capabilities both for the beginner and advanced malware reverse engineer, but we want fast indicators from our malware sample so that we can start defending against it immediately.
The REMNUX virtual machine is ready to go once imported into your virtualization platform with minimal modifications. We are simply going to add a network adapter in "host-only" mode and set the IP address to a non-routable IP. REMNUX will act as the internet "gateway" and DNS server for our victim machine. This will allow us to see all network requests and DNS requests that come from our infected victim host.
Infecting the Host
Now that you have the infrastructure in place, test your connectivity between the victim virtual machine and the gateway virtual machine. Have Wireshark running on the gateway box to verify successful connectivity. Attempt to SSH from your victim host to the gateway using putty. You can use "pscp.exe" within the Putty suite to move the original malware, and any malicious files the malware creates or drops onto your victim. Once you have moved the file over to your REMNUX host, you can take the MD5 of the original malware, before it is run. This will help in creating virus signatures and give you the required information for sharing within the CND community.
Utilizing "Regshot", take a snapshot of the "C:" drive pre infection, that way you will have something to compare after your host is infected. Regshot will record the current windows registry, all windows directories and files before infection, allow you to record again after infection, and then compare the changes made to the host.
You can now move your malware sample to the victim host. Ensure that you are running the necessary services and tools on your REMNUX host to capture the traffic. If you are not looking to interact with the malware, Wireshark can provide a wealth of data with not much in-depth knowledge. If you are looking to interact however, please consult the REMNUX readme for more information on "honeyd", "farpd" and "fakedns".
I also recommend running some kind of process explorer on the victim host to monitor what the malware does, any new processes it may spawn or kill. Sysinternals suite has several great tools, Process Explorer and Process Monitor are my two favorites.
Capturing the Indicators
Once executed on your victim host, you can record the information being fed to ProcMon, allowing you to watch what the malware does. You may see new applications start, processes get killed and new processes start. These are all indicators of the malware, and essential data to capture.
Watch your REMNUX host, check to see if any callouts are being made by the malware and see if it attempts to resolve DNS addresses. Often times once the DNS has successfully resolved, you will witness the malware attempt to connect to the Command & Control domain over an HTTP/HTTPS port.
A Note on DNS Resolution with Malware
The malware may attempt to resolve a known good website, this can be for internet connectivity checking as well as an attempt to fool someone monitoring it. If the malware is unable to resolve lets say “google.com” it may simply die on the victim host, and never try to reach the real command and control domain (CnC). This is when you want to have “fakedns” running on your REMNUX host, it will resolve any domain asked, this will then give the malware the positive connectivity test it is looking for, at which point may try to resolve the actual CnC domain.
Once you are satisfied with the length of time you have let the malware run, 10 minutes or less usually suffices, you can take the second “Regshot’ of the system. This will capture any changes made to the system by the malware. Once it has completed the second pass, compare the two and analyze the output. “Regshot” will reveal any new files created, deleted or modified. It will show you if any new registry keys were added or changed and any services that were created. It is an essential tool in the analysis toolbox.
As you can see with the "dir /ah" command, the files that were hidden on the victim. These files were all dropped from the malicious word document.
Once you have located the dropped or newly added malware on the victim host, you should move them over to your "REMNUX" host for analysis. These files are also indicators of a positive infection and should be included in your analysis of the initial malware. The MD5 hashes of these files are just as relevant for blocking and signature development as the principle delivery of these files, e.g. malicious word document, can easily change in future attempts.
Share Your Findings - One of the Most Important Pieces to Computer Network Defense
From this quick, and high level analysis of the malicious word document you were presented with several indicators that can benefit other Computer Network Defenders. One thing that I have learned is that not everyone catches or sees something the way I may I see it. So when I look at a piece of malware, no matter how simple I think it may be, I share it with the hopes that the indicators could assist others.
It is essential that you share as much information as you are comfortable with, as it may help to thwart future attempts against other targets. Collaboration amongst teams can help to stop these types of infections and identify current infections if they exist within your network. If possible, share any Command & Control Domains, MD5 Hashes, IP addresses, File Names and Sizes and anything else you feel is relevant to the infection.
The Internet of Things is clearly many things: data collection and analytics, wearables, Smart Grids and Smart Cities, the Industrial Internet, and more. Cool platforms like Arduino, Raspberry Pi, Intel's Galileo and Edison, and a diverse world of sensors are making the IoT a great toy box for developers in all these areas. In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists discussed what things are the most important, which will have the most profound...
Nov. 26, 2015 01:30 AM EST Reads: 417
In today's enterprise, digital transformation represents organizational change even more so than technology change, as customer preferences and behavior drive end-to-end transformation across lines of business as well as IT. To capitalize on the ubiquitous disruption driving this transformation, companies must be able to innovate at an increasingly rapid pace. Traditional approaches for driving innovation are now woefully inadequate for keeping up with the breadth of disruption and change facin...
Nov. 26, 2015 01:00 AM EST Reads: 426
Growth hacking is common for startups to make unheard-of progress in building their business. Career Hacks can help Geek Girls and those who support them (yes, that's you too, Dad!) to excel in this typically male-dominated world. Get ready to learn the facts: Is there a bias against women in the tech / developer communities? Why are women 50% of the workforce, but hold only 24% of the STEM or IT positions? Some beginnings of what to do about it! In her Day 2 Keynote at 17th Cloud Expo, San...
Nov. 26, 2015 12:00 AM EST Reads: 520
Discussions of cloud computing have evolved in recent years from a focus on specific types of cloud, to a world of hybrid cloud, and to a world dominated by the APIs that make today's multi-cloud environments and hybrid clouds possible. In this Power Panel at 17th Cloud Expo, moderated by Conference Chair Roger Strukhoff, panelists addressed the importance of customers being able to use the specific technologies they need, through environments and ecosystems that expose their APIs to make true ...
Nov. 26, 2015 12:00 AM EST Reads: 479
In his General Session at DevOps Summit, Asaf Yigal, Co-Founder & VP of Product at Logz.io, explored the value of Kibana 4 for log analysis and provided a hands-on tutorial on how to set up Kibana 4 and get the most out of Apache log files. He examined three use cases: IT operations, business intelligence, and security and compliance. Asaf Yigal is co-founder and VP of Product at log analytics software company Logz.io. In the past, he was co-founder of social-trading platform Currensee, which...
Nov. 26, 2015 12:00 AM EST Reads: 149
PubNub has announced the release of BLOCKS, a set of customizable microservices that give developers a simple way to add code and deploy features for realtime apps.PubNub BLOCKS executes business logic directly on the data streaming through PubNub’s network without splitting it off to an intermediary server controlled by the customer. This revolutionary approach streamlines app development, reduces endpoint-to-endpoint latency, and allows apps to better leverage the enormous scalability of PubNu...
Nov. 26, 2015 12:00 AM EST Reads: 278
Microservices are a very exciting architectural approach that many organizations are looking to as a way to accelerate innovation. Microservices promise to allow teams to move away from monolithic "ball of mud" systems, but the reality is that, in the vast majority of organizations, different projects and technologies will continue to be developed at different speeds. How to handle the dependencies between these disparate systems with different iteration cycles? Consider the "canoncial problem"...
Nov. 25, 2015 10:00 PM EST Reads: 389
Culture is the most important ingredient of DevOps. The challenge for most organizations is defining and communicating a vision of beneficial DevOps culture for their organizations, and then facilitating the changes needed to achieve that. Often this comes down to an ability to provide true leadership. As a CIO, are your direct reports IT managers or are they IT leaders? The hard truth is that many IT managers have risen through the ranks based on their technical skills, not their leadership ab...
Nov. 25, 2015 10:00 PM EST Reads: 342
I recently attended and was a speaker at the 4th International Internet of @ThingsExpo at the Santa Clara Convention Center. I also had the opportunity to attend this event last year and I wrote a blog from that show talking about how the “Enterprise Impact of IoT” was a key theme of last year’s show. I was curious to see if the same theme would still resonate 365 days later and what, if any, changes I would see in the content presented.
Nov. 25, 2015 09:00 PM EST Reads: 362
Apps and devices shouldn't stop working when there's limited or no network connectivity. Learn how to bring data stored in a cloud database to the edge of the network (and back again) whenever an Internet connection is available. In his session at 17th Cloud Expo, Ben Perlmutter, a Sales Engineer with IBM Cloudant, demonstrated techniques for replicating cloud databases with devices in order to build offline-first mobile or Internet of Things (IoT) apps that can provide a better, faster user e...
Nov. 25, 2015 08:30 PM EST Reads: 365
Container technology is shaping the future of DevOps and it’s also changing the way organizations think about application development. With the rise of mobile applications in the enterprise, businesses are abandoning year-long development cycles and embracing technologies that enable rapid development and continuous deployment of apps. In his session at DevOps Summit, Kurt Collins, Developer Evangelist at Built.io, examined how Docker has evolved into a highly effective tool for application del...
Nov. 25, 2015 05:00 PM EST Reads: 301
In recent years, at least 40% of companies using cloud applications have experienced data loss. One of the best prevention against cloud data loss is backing up your cloud data. In his General Session at 17th Cloud Expo, Sam McIntyre, Partner Enablement Specialist at eFolder, presented how organizations can use eFolder Cloudfinder to automate backups of cloud application data. He also demonstrated how easy it is to search and restore cloud application data using Cloudfinder.
Nov. 25, 2015 03:45 PM EST
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York and Silicon Valley. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place Nov 3-5, 2015, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 17th Cloud Expo and will feature technical sessions from a rock star conference faculty ...
Nov. 25, 2015 02:45 PM EST Reads: 493
Internet of @ThingsExpo, taking place June 7-9, 2016 at Javits Center, New York City and Nov 1-3, 2016, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with the 18th International @CloudExpo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world and ThingsExpo New York Call for Papers is now open.
Nov. 25, 2015 02:30 PM EST Reads: 506
The cloud. Like a comic book superhero, there seems to be no problem it can’t fix or cost it can’t slash. Yet making the transition is not always easy and production environments are still largely on premise. Taking some practical and sensible steps to reduce risk can also help provide a basis for a successful cloud transition. A plethora of surveys from the likes of IDG and Gartner show that more than 70 percent of enterprises have deployed at least one or more cloud application or workload. Y...
Nov. 25, 2015 02:15 PM EST Reads: 424