Showing posts with label execute malware. Show all posts
Showing posts with label execute malware. 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!

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.