SSL Proxy: Splunk & NGINX

Who is this guide for?

It is a best practice to install Splunk as a non-root user or service account as part of a defense in depth strategy. This installation choice comes with the consequences of preventing the Splunk user from using privileged ports (Anything below 1024). Some of the solutions to this problem, found on Splunk Answers require iptables rules or other methods. In my experience, the iptables method is not that reliable, and many newer distributions of Linux are abandoning iptables in favor of firewalld as the default host firewall. In this guide, I will show you how to use Nginx, and Let’s Encrypt to secure your Splunk Search Head, while allowing ssl traffic on port 443.



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Analyzing BotNets with Suricata & Machine Learning

Since the official rollout at the year’s. conf of the Machine Learning Toolkit(MLTK), Splunkers have been pursing some interesting use cases ranging from IT operations, planning, security and business analytics. Those use cases barely scratch the surface of what is possible with machine learning and Splunk. As an example, I will use the machine learning toolkit and data collected from Suricata to analyze botnet populations. This population analysis will be used to create a model for predicting the Mirai botnet based on network features.


Suricata is an open source threat detection engine, which can be run in passive mode for intrusion detection or inline for intrusion prevention. My lab environment is configured for intrusion detection, meaning Suricata will not …

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Enhancing Enterprise Security for Ransomware Detection

Ransomware isn’t going away

Ransomware is a profitable business model for cyber criminals with 2016 payments closed at the billon dollar mark. According to a recent survey by IBM, nearly 70% of executives hit by ransomware have paid to get their data back. Those survey results do not include smaller organizations and consumers who are also paying to get their data back.

With the threat from ransomware growing, aside from prevention, detection is key to removing compromised devices from the network. Unfortunately, signature based detection alone will not catch everything, instead using it in combination with hunting techniques in Splunk can enhance your security posture.  In this blog, we will walkthrough adding the free ransomware intelligence feed from to Splunk Enterprise …

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Analyzing the Mirai Botnet with Splunk

On September 20th, the largest Distributed Denial of Service attack ever recorded targeted security researcher Brian Krebs. This attack was made up of Internet of Things (IoT) devices such as cameras, wireless controllers and internet enabled devices peaking at 400,000 total. Now dubbed the “Mirai botnet”, these devices scanned the internet for devices running telnet and SSH with default credentials, infecting them and further propagating. The source code for the botnet has since leaked to GitHub, where further analysis is underway by security researchers.

During the infection time period, I happened to be running a honeypot and captured some infection attempts on my own system. Using Suricata and /var/log/secure.log I can correlate invalid login attempts associated with Mirai with malicious …

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Secure Splunk Web in Five Minutes Using Let’s Encrypt

Configuring SSL for your public facing Splunk instance is time-consuming, expensive and essential in today’s digital environment. Whether you choose to go with a cloud provider or self-hosting; RTFM-ing how to generate the keys correctly and configuring how Splunk should use them can be quite confusing. Last year, a new certificate authority Let’s Encrypt was born in an effort to streamline the CA process and make SSL encryption more widely available to users (The service is FREE). In this short tutorial, we will cover how to make use of this new CA to secure your Splunk instance and stop using self-signed certs.  Using SSL will help you to secure your Splunk instance against MITM attacks. Let’s Encrypt utilizes all of …

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