Showing posts with label malware execution. Show all posts
Showing posts with label malware execution. Show all posts

Thursday, December 10, 2020

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VirusTotal Multisandbox += Sangfor ZSand

VirusTotal multisandbox project welcomes Sangfor ZSandThe ZSand currently focuses on PE files,with extensions to other popular file types like javascript and Microsoft office to be released soon.


In their own words:
ZSand, developed by Sangfor Technologies’ Cloud Computing & Security Team, is an agentless behavioral analysis engine incorporating multiple innovative techniques. At the systems level, zSand employs Two-Dimensional Paging (TDP) techniques to inject hidden breakpoints, enabling accurate monitoring of the API calling sequence of a given process for further fine-grained analysis. At the GUI level, interactions are simulated by the virtual network console (VNC) and visual artificial intelligence (AI) techniques, providing a lifelike and fully functional sandbox. At the detection level, zSand identifies all forms of malware, including vulnerability exploits, by uncovering malicious behaviors and synergistically applying both conventional rule-based approaches and advanced AI algorithms. As a core innovation of the Sangfor anti-malware research group, zSand is a significant improvement in cyber-security capability for both Sangfor Technologies and its clients, customers and partners. Use cases include proactive hunting for unknown threats and the near real-time production of threat intelligence identifying malicious URLs, domain names, files, memory fingerprints, and malicious behavioral patterns. zSand is an agentless behavior monitoring engine, allowing users to deploy real-time defenses in a virtual environment.

In comparison with other sandboxes, the key advantages of zSand include:
  • High runtime performance -- By optimising the configuration of TDP and reducing the number of VMExit events, zSand minimizes monitoring overhead and resource utilization.
  • Strong anti-evasion measures -- Thanks to high performance hardware virtualisation and agentless features, zSand is immune to anti-sandbox detection. 
  • Comprehensive monitoring -- zSand retrieves detailed malware behavioral events and associated states of hardware including CPU, memory, disks, and network interfaces. 
  • Extensive and in-depth analysis -- Designed by cyber-security specialists and AI specialists, zSand is able to dynamically detect elusive and concealed malicious behavior, vulnerability exploits, malware persistence, and privilege escalation, at low levels.


Take take a look in the behavior tab to view these new sandbox reports:



Example reports:

You can also take a look at a couple of Sangfor ZSand behavior analysis reports here and here.
In case you are interested in searching for specific Sangfor ZSand reports, VirusTotal premium services customers may specify so using sandbox_name:sangfor in their queries.

Pivot on interesting behavioural characteristics

All malware uploaded to VirusTotal is detonated in multiple sandboxes, providing security analysts with many interesting and powerful possibilities. Having multiple fine-tuned sandboxes increases the possibilities of malware detonating properly (remember malware usually implements different anti-sandboxing techniques), and provides valuable dynamic data on how the malware behaves.


Why is this data valuable? Because it gives us details that are not visible at static analysis time. For instance, we can use this data to land some TTPs into something more actionable. We will get back on this topic on a future blogpost.


For example, taking in the following sandbox report we find some potentially interesting mutex names. 


We can use this data to pivot and find other malware having the same mutexes when detonated on our sandboxes. By clicking on one of the interesting mutexes, in this case ENGEL_12, we will create a new search ( behaviour:ENGEL_12) which provides us with samples belonging to a common family of padodor malware.




It turns out that this is a valuable dynamic indicator we can use to identify malware samples belonging to this particular malware strain.   From VirusTotal, we welcome this new addition to our Sandboxing arsenal. Happy hunting!

Thursday, October 24, 2019

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Revamping in-house dynamic analysis with VirusTotal Jujubox Sandbox

VirusTotal Jujubox Sandbox in action:



This is a small datastudio set up to illustrate the kind of analytics that can be built with a massive dynamic analysis setup, generating IoCs. Note that there are several pages.


One of the main themes of VirusTotal’s 2019 roadmap is “Holistic Threat Profiling”. Some users never move beyond the basic use case for VT: checking hashes and looking at detections. However, that use case, while still core to VT, is by no means the most popular. VT also provides information on URLs, IPs and domains, and what’s more, it builds a graph that relates all of these observables. In an effort to allow users to identify the complete attack campaign, beyond the individual malware variants, we continue to introduce new tools and features. This new functionality allows users to characterize a threat from different points of view: static analysis, dynamic analysis, code analysis, relationship analysis, and more.

In our ongoing efforts to improve our behaviour analysis infrastructure we are happy to announce the rollout of a new Windows Sandbox that radically improves and complements our previous Windows XP SP1 analysis systems that was launched in 2012. The analyses generated by this new system are seamlessly showing up in new file reports, freely for the community. We are also complementing our threat feed offerings with a dynamic analysis feed derived from this new system, more on this later, let’s first focus on the community impact.

The project has been baptised as “Jujubox” (a reference to the type of bad karma - juju- objects it processes) and integrated in the context of the multi-sandbox project. This new sandbox is currently running Windows 7 and records the actions of Windows 32bit and 64bit binaries under 80MB when executed. It extracts information such as:

  • File I/O operations.
  • Registry interactions.
  • Network traffic: HTTP calls, DNS resolutions, TCP connections, DGAs, etc.
  • JA3 digests.
  • Dropped files (and the interrelations between them).
  • Mutex operations (Creation, Opening).
  • Runtime Modules
  • Highlighted text in windows, dialogs, etc.
  • Highlighted winapi/syscalls
  • AND MUCH MORE.
 
The information from the execution is indexed and searchable through VT Enterprise and fuels services such as VT Graph. Basically, any text found in these reports is indexed in an elasticsearch database. Each analysis also contains a fully revamped detailed HTML report, with improved filtering capabilities, allowing analysts to grasp the details of sample execution: syscalls, process tree and screenshots.






In order to access the detailed HTML report containing all windows API calls you just need to refer to the multi-sandbox action menu bar:



The detailed HTML report logs API calls and return values, meaning that it can greatly expand the observations contained in the summarized report view. You may refer to the following report in order to see an example of the full HTML report:
https://www.virustotal.com/gui/file/7d77b3325afb5fe035ec7d3be6834570ce0c57088a90b15ebf73ce34211f59ff/behavior/VirusTotal%20Jujubox

Let’s take a look at some specific use cases that can be solved with this new setup.

 

Pivoting and mapping threat campaigns

After the analysis we can gather information from the sample and use it to either find relationships with other elements or to pivot to other campaign artifacts. This is an example illustrating the sandbox analysis:



This new setup contributes to the relationships created between samples and domains, allowing us to appreciate the DGA used by this particular malicious sample. The same goes for its dropped files. The sandbox analysis acts as a microscope, allowing us to better understand an individual threat. For instance, we can also take a look at where this malicious sample usually stores itself for persistence by checking the copied files and registry keys set:




Using inline hover pivots it is easy to find other reports showcasing this very same behaviour:
https://www.virustotal.com/gui/file/7d77b3325afb5fe035ec7d3be6834570ce0c57088a90b15ebf73ce34211f59ff
https://www.virustotal.com/gui/file/f803e20e6dedb82ff778d8af9beead6fd8e07ae15425da03dc0654ca620ef2ac
https://www.virustotal.com/gui/file/09414ae9bf7be94edebe16546070ea219f3782bf0b83eabf10af6355ae531509
https://www.virustotal.com/gui/file/4de0f87fabf2f4dadd519f7a4ae7ca04207d7d8b0bf0661d8b60521f5cc3e59b/behavior/VirusTotal%20Jujubox

To pivot even further and find other similar files, we can use one of the advanced search operators to focus on file activity:
behaviour_files:"C:\Program Files\AVG\AVG9\dfncfg.dat" and sandbox_name:jujubox

Once you have discovered several variants pertaining to the same threat actor, it might be a good time to build a YARA rule and feed it into VT Hunting in order to track the evolution of the given malware family and understand better the attackers behind it.

 

Finding similar samples by mutexes

Mutexes are often reused by many samples, although most of them are usually common and legit, malware often chooses very characteristic names for its mutexes, making it easy to identify families and threat campaigns. This sample is a perfect example, it has a very specific mutex name:



By clicking on the mutex name we can find samples sharing the same behavior when it comes to mutex creation. Within VT Enterprise we can execute the query behavior:sfdkjjhgkdsfhgjksd to find such samples.


 

Pivoting on JA3

JA3 hashing is a way to fingerprint TLS client connections. In this particular report we can see a JA3 hash:



To pivot on this JA3 we click on the hash and generate the pertinent search query. This will use the behavior search modifier:
behavior:"706ea0b1920182287146b195ad4279a6"



Another JA3 example is to search for samples that use a Tor client:
behavior:"e7d705a3286e19ea42f587b344ee6865"

 

Programmatically interacting via API

All of the data described above is freely surfacing in APIv3, giving users a complementary characterization of their files beyond file reputation. A common use case is VT Enterprise users setting up YARA rules in VT Hunting in order to track malware variants or threat actors and then automatically retrieving file behavior reports for their notifications. These file behaviour reports are then data mined for patterns in terms of mutexes, contacted domains, file naming conventions, etc. in order to generate indicators of compromise that can be used power-up security defenses.

The following datastudio showcases the kind of insights that can be derived from aggregated study of behavioral observations, it clearly illustrates that by focusing on volume, and beyond that on malware families and clusters, it is sometimes straightforward to identify patterns and commonalities in order to generate alternative detection mechanisms for threats. Note that this datastudio has several pages.


 

Sandbox feed

This important effort to improve our free community capabilities is also being leveraged to radically improve our premium services. As seen in the datastudio above, when operating at scale we can make use of clustering and data mining in order to generate patterns and commonalities that can be fed into security defenses as yet one more mechanism in our onion layered security model.

As such, we are creating a new offering that expands our portfolio of feeds (file and URL feed), allowing users to retrieve all the dynamic analysis reports generated for files uploaded to VirusTotal. The value proposition is simple:
  • Ingest every single sandbox dynamic analysis report generated for all files which are analyzed within VirusTotal sandbox. As of October 2019, we do our best to sandbox all PE EXE, MSI, Android, MacOS Mach-O/DMG/PKG files.
  • Datamine the feed and identify domains, IP addresses, URLs, mutexes, registry keys, etc. that may be used as indicators of compromise to power-up your security toolset.
  • Discover unknown malware flying under the radar of antivirus solutions by studying behavioral patterns.
  • Implement complex behavior detection rules.

If you are interested in getting Early Access Preview to this service feel free to reach out to us. In future blog posts we will dive deeper into how the sandbox feed can be leveraged to improve security defenses, stay tuned.

Wednesday, October 23, 2019

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VirusTotal multisandbox += VenusEye

VirusTotal multisandbox project welcomes VenusEye. The VenusEye sandbox is currently contributing reports on PE Executables, documents and javascript.

In their own words:

VenusEye Sandbox, as a core component product of VenusEye Threat Intelligence Center, is a cloud-based sandbox service focused on analyzing malwares and discovering potential vulnerabilities. The sandbox service takes multiple(~100) types of files as input, performs both static analysis and behavior analysis after then, and eventually generates a detailed human-readable report in several supported formats like PDF or HTML. Being weaponized with MITRE ATT&CK knowledge base, VenusEye Sandbox combines the product and the service as a whole. With the help of our sandbox service, users can track threat actors or gather threat intelligence for their hunting in a much easier way.

You can find VenusEye reports under the “Behavior” tab:




Take a look at a few example reports within VirusTotal:
https://www.virustotal.com/gui/file/e728fbb5099d17dbe43b48e2fb5295fdd8a25f3790aac3e353c609b1745bd432/behavior/VenusEye%20Sandbox
https://www.virustotal.com/gui/file/6d395a6e0c6899b7bf827099f30cb5abf2da0e6bb766d730cf9cbe014b5e6a9f/behavior/VenusEye%20Sandbox
https://www.virustotal.com/gui/file/8c64086f3a31ebd87963b832e1327587499e0866dce9ad865363d2d2cb8b40c9/behavior/VenusEye%20Sandbox
https://www.virustotal.com/gui/file/0883847c6958cac651ebc2764ec5a5e223d29d5a0a80cb9e08b8ec83bfde6f00/behavior/VenusEye%20Sandbox
https://www.virustotal.com/gui/file/8143a2c2666575152896609c1d8d918717a358d4611a57a0cce2559e3c5cabbf/behavior/VenusEye%20Sandbox

Document with macros

Taking a look at the embedded content preview for the sample 8143a2c2666575152896609c1d8d918717a358d4611a57a0cce2559e3c5cabbf we see that the malware is attempting to trick users to enable macros.



The VenusEye sandbox automatically enables macros and allows us to see the execution details, including the HTTP requests, DNS resolutions and process tree.



Javascript files

Wide use of online email services that automatically block executable attachments has led to attackers using alternative file formats for their spam campaigns. As depicted above, documents with macros are one example, Javascript files have also become quite popular. VenusEye represents a very interesting addition to the multi-sandbox project in that, unlike some of the other integrated sandboxes, it also analyses javascript files.



In this particular example, the simple fact that a javascript file that can execute in Windows (as opposed to being a website resource) performs DNS resolutions should be enough to consider the file highly suspicious. More so if we take into account the registry keys with which it interacts:



Rich relationships

The two examples above illustrate VenusEye acting as a microscope to understand what an individual threat does. However, thanks to the network traffic recordings, VenusEye also contributes macroscopic patterns that can be easily understood using VT Graph.

For example, when looking at the javascript file above we can make use of the file action menu in order to open it in VT Graph:



By default a one level depth inspection is performed, but we can always dig deeper. By expanding the files communicating with poly1374.mooo.com we get to discover a Windows executable that seems to be using such domain as its command-and-control:



In other words, VenusEye also helps in tracking entire campaigns thanks to the contributed file/domain/IP/URL relationships.

Advanced pivoting

As usual, all of this information is indexed in the elasticsearch database powering VT Enterprise, this makes it trivial to pivot to other variants of a given malware family or other tools built by a same attacker.

Let us now return to the document with macros above, VT Enterprise users can click on any of the behavior report contents in order to launch a VT Intelligence search for files exhibiting the same pattern when executed. Let us click on the first HTTP request entry:



This launches the search behaviour_network:"http://mediaprecies.online/cgi-bin/58lt9/", finding other samples that communicate with that very same URL. Now that we have identified other variants belonging to the same campaign or threat actor, it is trivial to automatically generate commonalities that we can use as IoCs to power-up our security defenses:



Thank you VenusEye for joining the multi-sandbox family that aggregates more than 10 dynamic analysis partners and counting. If your organization has some kind of dynamic analysis setup, don’t hesitate to contact us to get it integrated in VirusTotal, we will be more than happy to grant you free VT Enterprise quota in exchange.

Tuesday, June 05, 2018

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Multisandbox project welcomes Dr.Web vxCube


The multisandbox project keeps growing, short after the integration of Tencent Habo, VirusTotal Droidy and Cyber adAPT ApkRecon we are now welcoming Dr.Web vxCube. What is most exciting about this integration is that not only does it run executables, but also opens documents with potentially vulnerable software in order to spot exploits and characterize dropped malicious payloads.


In their own words:
Dr.Web vxCube was born inside Doctor Web Anti-Virus Laboratory. It is a hypervisor-based sandbox that uses agentless technology to analyze malware inside the operating system. It works incredibly fast and invisibly to the analyzed sample. Dr.Web vxCube offers comprehensive but intuitive reports containing information about sample's behavior, created files and dumps, process graph, API log and network activity map. We are happy to bring our expertise to the VirusTotal community.


The following report examples highlight how useful this new integration is:


The following ones are particularly interesting as they exemplify how Dr.Web vxCube is able to spot exploitations triggered when opening a document, most specifically exploitation of CVE-2017-11882:


Make sure you also open the detailed report:

This will open up a far more insightful HTML capturing fine grained execution details that are presented in an aggregate fashion in the summarized behavior tab or perhaps not even included at all:


Behavior information is essential when diving into investigations because it allows analysts to pivot over certain indicators of compromise and discover other malicious files and network infrastructure that is related to the same campaign or attacker group. For instance, if we focus on the first CVE-2017-11882 file and open it up in VirusTotal Graph:



We can immediately get a sense of the file indeed being malicious (due to its connection to malicious items) but we may also easily discover the network infrastructure used by it, and most importantly, we get to see other malware served by that very same network infrastructure, without having to follow a huge amount of report links:



And this is precisely how we discover some of the deception techniques being used by the attackers behind this particular threat. The exploiting document communicates with a-dce.com, so do 3 other samples. By investigating these in VirusTotal Intelligence we get to see that some of those files were spotted as attachments in spam email files uploaded to VirusTotal, we can see the body of these messages and discover how they trick users into downloading and opening the exploiting document:





Fake purchase orders and invoices remain a common simple bait inducing users to execute malware. Having reached this point it would be a good moment to build a Yara rule to detect variants of this malware family and set them up in Malware Hunting in order to discover new threats created by the very same group and keep expanding the investigation graph.

We hope you find this new sandbox as exciting as we do. We already have more integrations in the pipeline and we are certain this will heavily contribute to identifying new threats and strengthening anti-malware defenses worldwide.


If you have a sandbox setup or develop dynamic malware analysis systems please contact us to join this effort.