Pressure is increasing on manufacturers to monitor their shop floors for malicious activity to avoid creating major disruptions in the supply chain. One key security defensive tool for monitoring network-connected devices in a manufacturing environment is Operational Technology Security or just OT. Let’s look at what OT is and how it can detect malicious activity.
OT vs IoT
OT and Internet of Things (IoT) are commonly confused, so here’s a brief description for each.
OT is short for Operational Technology, which refers to all network connected devices used in an industrial (or operational) architecture. IoT is the acronym for Internet of Things, which generally refers to all network devices beyond those that make up the traditional network (routers, switches, servers, etc.).
Examples of OT devices include:
- Shop floor robotics
- Intelligent oil and gas connected machines
- Smart electrical grid appliances
Examples of IoT devices include:
- Smart TVs
- Network connected cars
- Door cams
How is OT Monitoring Unique?
Detecting OT threats usually involves sniffing the network(s) for protocol-specific anomalies.
For example, industrial network systems commonly use the CIP (Common Industrial Protocol) and this is also frequently targeted by attackers. As such, you wouldn’t expect there to be your typical IOCs like public IP addresses and hashes that you could use to detect threats. Instead, you would need to sniff the factory network, looking for malicious use of the CIP protocol. This is where OT security tools come in. A recent example of a high-risk OT vulnerability is CVE-2023-3595. This vulnerability has a CVSS score of 9.8 (i.e., very bad).
Who needs OT?
OT is commonly used in any physical environment where operationally critical, network-attached hardware is located. Given the incredible expansion of distinct devices employing network connectivity, OT sensors can provide excellent insights into an organization’s attack surface view.
Examples of Industries using OT security include:
- Manufacturing
- Oil and gas
- Electrical generation and distribution
- Transportation – air, land, sea Utilities
- Financial
- Government agents involved with national security
OT Architecture and Deployment Example
Modern OT architectures typically include 1 or more sensors and a Management Console:
OT Sensors
- OT sensors will have at least two network interfaces. One is connected to the network and the other to the Internet for uploading telemetry to a cloud-based management system. The sensor doesn't allow routing of any traffic in or out of the OT network and in a more restrictive, air-gapped environment, the sensor may be redirected to a secure gateway to add an additional layer of defense.
Image 1: Example of an OT sensor shipped straight from the vendor with pre-installed software.
OT Management System
The OT Manager could be an on-prem server, but these days it’s commonly in the cloud. The OT Manager provides some or all of the following features:
- Visualization of alerts sent by the OT sensors
- Additional correlating of alerts to identify more complex attacks
- Upgrading of OT sensor images and configurations
- Creation of custom alerting and reporting
- Sharing of alert telemetry with other security tools such as SIEM
Image 2: OT/IoT Management System. Ref. Microsoft’s Defender for IoT solution.
Advanced Features
The features provided by each OT security vendor will vary. Here are some advanced features to look out for:
Summary
Modern OT security solutions can be quickly deployed and centrally maintained in a variety of environments and industries. OT security architecture can provide an extension to a security team’s attack surface perspective by protecting supply chains that use operational technology.
References
About This Blog Series
Follow the full series here: Building Defenses with Modern Security Solutions
This series discusses a list of key cybersecurity defense topics. The full collection of posts and labs can be used as an educational tool for implementing cybersecurity defenses.
Labs
For quick walkthrough labs on the topics in this blog series, check out the story of “ZPM Incorporated” and their steps to implementing all the solutions discussed here.
Compliance
All topics mentioned in this series have been mapped to several compliance controls here.
David Broggy, Trustwave’s Senior Solutions Architect, Implementation Services, was selected last year for Microsoft's Most Valuable Professional (MVP) Award.
