"ATT&CK"ized Splunk

Most of us know MITRE and the ATT&CK™ framework that they have come up with. What a splendid job they have done for the cyber security community by bringing most of the key attack vectors under an organized framework that segregates these attack vectors in various stages of a typical attack. Not only they have orchestrated the key attack vectors but the mitigation and detection guidance for each attack vector are also part of this framework. Furthermore, the information about the threat actors, who are seen using these attack vectors in-the-wild, is also associated with every attack vector. Together, it is a complete package that any Threat Defense/IR team likes to have with them.

Apparently, ATT&CK has received an overwhelming response from the community and in fact, every SIEM or Threat detection vendor out there in the market has started aligning their products to MITRE’s ATT&CK.

Previously, this information on Indictors of Compromise (IOCs) was subject to a few threat intel individuals who used to provide inputs to the detection teams (blue teams) to improve on their detection capabilities and required to fetch from various free/paid threat intel reports. With ATT&CK in place, we are covered with these basic IOCs that every IR team should care about. 

Now, the moot question is how to actionize ATT&CK framework.

There are many genius people out there in the world to solve such problems and one of them is Olaf Hartong. He has developed a super cool app named “ThreatHunting” for Splunk that sits on top of Splunk Enterprise and gives us a very intriguing dashboards which are aligned with MITRE’s attack. The following is the screenshot of the overview dashboard of this App. 

This is the exact dashboard which one would have thought while going through MITRE’s ATT&CK framework.  

You can find the repo on the git hub here: ThreatHunting. The same can be found on splunkbase here: https://splunkbase.splunk.com/app/4305/

I am writing this blog to explain how to install and make this app up and running as it might get tricky when you actually start using it.

Pre-requisites:

1.     Sysmon logs from your environment

2.     A few apps

Install the following apps to your SearchHead:

a.     Punchcard Visualization

b.    Force Directed Visualization

c.     Sankey Diagram Visualization

d.    Lookup File Editor

So, let us start with prerequisites

Step 1: Sysmon logs : I hope all of us are familiar with Sysmon. If not, nevermind. no big deal. Have a look at this link https://docs.microsoft.com/en-us/sysinternals/downloads/sysmon

Sysmon does not log all the events by default hence the configuration file needs to be altered. SwiftOnSecurity’s sysmon-config project will come to our rescue and save our lot of time of developing this config file.

The only caveat to this is - as they say “nothing is perfect” in this world - so you may find some configuration issues here-and-there in the file that you might need to rectify manually.

For example, after I install and configure the sysmon with this configuration file, any modifications to AppInit_DLLs registry were not getting logged while it should because the following two lines were the part of my configuration file to catch them 

<TargetObject condition="begin with">HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows\Appinit_Dlls\</TargetObject>

<TargetObject condition="begin with">HKLM\SOFTWARE\Wow6432Node\Microsoft\Windows NT\CurrentVersion\Windows\Appinit_Dlls\</TargetObject>

It turns out removing ‘\’ after Appinit_Dlls in above lines, it started logging the changes to AppInit_DLLs. So, such things can be figured out with experience and trial& error. So, watch out for those misconfigs !!

Downloading and Installing Sysmon:

Download Sysmon from https://docs.microsoft.com/en-us/sysinternals/downloads/sysmon

Download sysmonconfig-export.xml file from https://github.com/SwiftOnSecurity/sysmon-config and keep it in the same folder where Sysmon is kept.

This will install Sysmon with the specified configuration in the config file. You need to tweak the config file as I mentioned above when required.

You can find the sysmon logs under eventviewer under Applications and Services Logs/Microsoft/Windows/Sysmon/Operational 

Step 2: Installation of Pre-requisite Apps

Then install the above-mentioned pre-requisite apps from the Splunkbase on to the Splunk search head. It should look like as following 

Step 3: Okay, now, it’s time to install the “ThreatHunting” app which is available on the Splunkbase.

Hence, go to “App Management” console on the Splunk search head and click on “brose more apps” button and search for ThreatHunting app. 

Click on the install button and it will get installed. With this, you have added “threathunting” and “windows” index to your index list which will be used later in the configuration.

Step 4: Update the "ThretHunting" configuration

Once you are done with that, we need to ingest our Sysmon data if not ingested already. I am using stand alone instance of the Splunk for this demo purpose, however, you may ingest the data the way you are doing it for other similar logsources. The keypoint here is to ingest this data in “windows” index.

PS: You can ingest this data in any index that you want but then you got to modify the ThreatHunting App’s configuration accordingly. 

The following are the steps to get the Sysmon data in for a standalone instance of Splunk. 

Go to Settings-->Data-->Data inputs 

Select Microsoft-Windows-Sysmon/Operational from Available log(s) and select the index “windows” from the dropdown box as shown below

and click save.

Go to ThreatHunting App and click on “About this app” and click on “Edit Mocro’s here” 

Go to “sysmon” in the macro and update the index and the sourcetype that you are using.

Default config comes with sourcetype as“sourcetype="XMLWinEventLog:Microsoft-Windows-Sysmon/Operational" which needs to be changed as shown above in the snippet. At the same time, props.conf also needs to be changed with the correct sourcetype. Go to splunk/etc/apps/threathunting/default/props.conf and change the sourcetype as shown in the figure below. 

Finally, you have to upload the lookups to the lookup folders in the App. Download the lookups from here and past them under lookups. These are blank lookups, you may need to populate them with actual whitelisting data. 

Once that is done, we are done with the basic config and it’s a show time. Go to the ThreatHunting App and click on the “Threat Hunting trigger overview” and if you are luck your dashboard should have started populating with the data in your environment. 

Now, mind you, this will again open the flood gates and your dashboard might get populated with exaggerated numbers. As I said earlier, This App comes with Whitelisting lookups that you may need to update with the Whitelist entries – that would help in reducing to the real suspicious events that you want to investigate. Nonetheless, this exercise will give you a deep insight about how your environment works.

Happy hunting, fellas!! 

Update : Aug-2019

I have recently downloaded and deployed latest version of ThreatHunting App (1.4.1). This has removed the need of changing "Sourcetype" in macro as well as in props.conf as macro and props.conf have been updated for both of the sourcetypes in a new version of the App. Rest of the steps are still valid of this guide.