Used by more than 10,000 organizations around the world, OSSEC has provided an open source alternative for host-based intrusion detection for more than 10 years. From Fortune 10 enterprises to governments to small businesses, OSSEC has long been a standard part of the toolkit for both security and operations teams.
As more organizations move to the public cloud infrastructure and to DevOps and DevSecOps processes, OSSEC is finding new use cases and attracting new fans. Downloads of the project nearly quadrupled in 2018, ending the year at more than 500,000. Much of this new activity was driven by Amazon, Google, and Azure public cloud users.
While many security and operations engineers are familiar with OSSEC in the context of on-premise intrusion detection, this article will focus on the project's growing use and applicability to cloud and DevSecOps use cases for security and compliance.
OSSEC offers six key intrusion detection capabilities to users in any environment, on physical servers, in containers or virtual machines, or in public or private clouds.
- Log-based intrusion detection (LIDS): Actively monitors and analyzes data from multiple log data points in real time.
- File integrity monitoring (FIM): For both files and Windows registry settings in real time, detects changes to the system, and maintains a forensic copy of the data as it changes over time.
- Rootkit and malware detection: Process- and file-level analysis detects malicious applications and rootkits.
- Compliance auditing: Application- and system-level auditing ensures compliance with many common standards, such as PCI-DSS and CIS benchmarks.
- System inventory: Collects system information, such as installed software, hardware, utilization, network services, and listeners.
- Active response: Responds to attacks and changes on the system in real time through multiple mechanisms, including firewall policies, integration with third parties such as content delivery networks and support portals, as well as self-healing actions.
OSSEC provides intrusion detection capabilities on Linux, MacOS, and Windows, as well as on legacy operating systems, including AIX, HP-UX, and Solaris. This gives operators the ability to run a single host-based intrusion detection system (HIDS) across an entire environment.
Many organizations integrate OSSEC with a security information and event management (SIEM) system, such as Splunk, ArcSight, Elasticsearch, or QRadar, to pipe events to their security operations center (SOC). In this case, OSSEC plays the role of a log aggregator and only sends actionable information to the SIEM. This reduces data volume in the SIEM, which cuts down on noise for SOC personnel and often results in dramatic reductions in SIEM costs.
The Cloud and DevSecOps Imperative
As public cloud customers are discovering, moving to the cloud presents a host of security and compliance responsibilities for enterprise security and IT teams. While cloud providers handle hardware and infrastructure, cloud workloads themselves must be secured by the customer.
This fact is often obscured in the quest for cost savings and efficiencies of the public cloud. However, all major cloud providers publish "shared responsibility matrices" that highlight which security and compliance requirements are owned by the customer. This can be summarized nicely by Amazon as "Amazon is responsible for security and compliance of the cloud, the customer is responsible for security and compliance in the cloud."
This leaves the enterprise with the need to bring its own security and compliance tools to the cloud. And traditional on-premise controls and network security don't work in the perimeter-less software defined environment of the public cloud. Security must be built directly into the workload.
In this area, the cloud presents another challenge: Whatever additional security and compliance tools are added to the workload will increase the cost of cloud usage. In on-premise environments, enterprises do not need to concern themselves with the amount of computing resources consumed by their security software. In the cloud, this can cost real money.
OSSEC provides a solid foundation to meet multiple security and compliance requirements not handled by the cloud provider. It is installed directly on the workload and offers all of the same functional capabilities outlined above.
From a cost perspective, OSSEC offers two distinct advantages. First, it's open source, so users can get started for free and without enduring long and complicated procurement processes. Perhaps more importantly, OSSEC runs in a very small footprint. When added to a cloud workload, it typically adds less than 3% overhead, which means it will have almost no impact on cloud usage costs.
Most organizations moving to the public cloud have also adopted a DevOps process with hundreds or even thousands of releases a week. To effectively secure these releases, security tools must be deployed easily using DevOps orchestration tools such as Ansible, Puppet, and Chef. OSSEC easily integrates with these tools as well as custom scripts to ensure it can be deployed with every release.
Getting Started with OSSEC
OSSEC is free and licensed under the GNU Public License. The project may be downloaded here, along with documentation, release notes, and options for commercial support and advanced functionality.
The annual OSSEC user conference will be held March 20-21 in Herndon, Virginia. The agenda includes a keynote talk from Daniel Cid, the founder of the OSSEC project, how-tos from OSSEC contributors and power users, and hands-on tutorials and workshops. Click here to learn more.
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Join Dark Reading LIVE for two cybersecurity summits at Interop 2019. Learn from the industry's most knowledgeable IT security experts. Check out the Interop agenda here.