Imagine a world where most of your security stack seamlessly integrates with each other, has access to the latest threat intelligence from internal and external sources, and automatically mitigates the most severe incidents. Suspicious files found in emails get sent to the closest sandbox for detonation, where the hash and other IOCs are sent to endpoints, NGFWs, proxies, etc. to inoculate the organization, and then send all of the relevant information to the SOC as an incident ticket.
Many organizations can at least do the above with a Security Orchestration Automation and Response (SOAR) platform implementation. Several vendors offer this type of Orchestration platform, including Splunk (Phantom), Palo Alto Networks (Demisto), Fortinet (Cybersponse), and IBM (Resilient). These platforms have become mainstream within the past few years and with more and more cybersecurity professionals learning the python programming language it has become easier to implement and customize them. In fact, no programming experience is needed at all for many use cases since playbooks can be created and maintained with a graphical builder.
I’m a big fan of using Orchestration to automate workflows with playbooks – in fact I’ve written a couple of these integrations before for Phantom and Demisto. But there is another automation paradigm that doesn’t get talked about as much in the cybersecurity realm: Choreography.
So we already have an idea of what Orchestration is: it’s a central repository of vendor integrations and associated actions that can be connected together in clever and novel ways to create playbooks. Playbooks are like scripts that run based on incoming events, schedules, or can even be run manually to automate repetitive tasks. This automation removes the human-error factor and can reduce the workload of the Security team.
The key piece about Orchestration is that it is centralized. There is typically a central server that has all of the vendor integration information and playbooks. Alarms, logs, alerts, etc. get sent to this server so it can act as the conductor and tell each security device in the stack what to do and when to do it.
This approach has pros and cons:
- Very flexible – you can make a playbook do almost anything you can think of
- Can version control the playbooks in a central repository like git
- Large libraries of vendor apps
- Typically have a good user communities
- Can be brittle if APIs change, unsupported vendors are introduced, or if there are connectivity issues to the central Orchestrator
- Vendor lock-in to a SOAR platform / not open source
- Can require python programming experience to onboard an unsupported security service or to create a complex playbook
Let’s compare this to Choreography – the other, lesser-known automation paradigm available to us.
Choreography? Where did that come from? Well, the concepts of Orchestration and Choreography come from the world of Service Oriented Architecture (SOA). SOA had some good ideas, but it didn’t really take off until it recently morphed and rebranded as Microservice Architecture. (Yes, this is an over-simplification for the scope of this post)
We almost take microservice architectures for granted now. Cloud application delivery and containerization of services are not as bleeding-edge as they were just a couple of years ago. We intuitively understand that microservices act independently yet are connected to other microservices to make up an application. The way these microservices are connected can be described as Orchestration or Choreography.
Now we are just extending the metaphor and considering each piece of our security stack as a ‘microservice’. For example, your NGFW, sandbox, email security gateway, NAC, Intel feed, etc. are all cybersecurity microservices that need to be configured to talk to one another to enable your cybersecurity ‘application’.
In the case of Choreography, each of these security ‘microservices’ (or security appliances) knows what they are supposed to do by subscribing to one or more channels on a message bus. This bus allows the service to receive alerts and IOC information in near-real-time and then publish their results on one or more channels on that same bus. It’s almost like layer 7 multicast for you router geeks out there.
In this paradigm, there is no need for a central repository of rules or playbooks for many standard use-cases because the ‘fabric’ gets smarter as more and more different types of security services join. Unlike an orchestra, which follows the lead of the conductor, each service works independently based on its own configuration. Each service knows its own dance moves and works harmoniously in relation to the other services.
The Message Bus
How does this work in the real world?
There are a couple examples of the Choreography approach being used in the Cybersecurity realm. A proprietary implementation by Fortinet (disclaimer: I am a Fortinet employee) is called the “Security Fabric”.
Fortinet Security Fabric
Fortinet’s Security Fabric is a proprietary implementation that behaves like a message bus to learn about new Fortinet and Fabric Ready ecosystem partner appliances and services as soon as they connect to the fabric. These services are configured to connect to the Security Fabric and take appropriate action when a security incident is identified.
For example, after installing a FortiSandbox appliance and adding it to the Security Fabric, other Fortinet or “Fabric-Ready” partner appliances, such as the NGFW and Secure Email Gateway can send suspicious files they detect to the Security Fabric where the sandbox service is listening. The FortiSandbox, in turn, can publish the IOC results of the scans it performs to the Security Fabric so other Fortinet or Fabric-Ready partner appliances (e.g. NGFW, FortiGuard, FortiEDR) can ingest them and take appropriate action.
This is very powerful. As more services are connected to the Security Fabric, it gets smarter, more capable, and scales – automatically.
Another open-source, multi-vendor example of a message bus being used for cybersecurity choreography is OpenDXL. OpenDXL was originally developed by McAfee, as a security-specific message bus, but it was open-sourced under the Organization for the Advancement of Structured Information Standards (OASIS) Open Cybersecurity Alliance (OCA) project. (Disclaimer: Fortinet is a sponsor of OCA) This project brings together the message bus concept to integrate multiple cybersecurity services using well-known formats like STIX2 to influence its ontology.
Some of the pros and cons of the Choreography approach:
- The ‘fabric’ automatically gets smarter and more capable as more security services are connected
- No need for dozens of boilerplate playbooks
- Open-source and proprietary options available
- No reliance on a central conductor – less brittle to Orchestrator outages or misconfigurations.
- Integrations “just work” together if they are part of the ecosystem
- Less granular control over automation workflows
- Open-source options are still maturing
- Typically, no central repository for service configurations
Which Way is the Best?
We know that automation will improve our security operations, but which approach is best? Since Orchestration and Choreography both have their own pros and cons that don’t overlap too much it probably makes sense to use both.
Choreography can reduce the amount of boilerplate playbooks you need to bootstrap your automation initiative, while Orchestration can be used to automate higher-level business or incident response workflows.
By applying the application architecture concepts of SOA and microservices to cybersecurity we can take security automation to the next level.