You can find Home Assistant systems using this tool.
Home Assistant is a free and open-source software for home automation that is designed to be the central control system for smart home devices with focus on local control and privacy. It can be accessed via a web-based user interface, via companion apps for Android and iOS, or using voice commands via a supported virtual assistant like Google Assistant or Amazon Alexa. IoT technologies, devices, software, applications and services are supported by modular integration components, which not only include native integrations for local connectivity protocols like Bluetooth, MQTT, Zigbee and Z-Wave, but also support for controlling proprietary ecosystems if they provide access via a public API for third-party interfaces. After the Home Assistant software application is installed as a computer appliance it will acts as a central control system for home automation (commonly referred to as a smart home "hub", "bridge", "gateway", "controller", or "coordinator"). Information from all entities it sees can be used and controlled from within scripts trigger automations using scheduling and "blueprint" subroutines, e.g. for controlling lighting, climate, entertainment systems and appliances.
If attackers detect the technology used, they will try to detect vulnerabilities related to this application.
Only use components that do not have known vulnerabilities, only use components that when combined to not introduce a security vulnerability, and ensure that a misconfiguration does not cause any vulnerabilities.