Does Microsoft Defender Antivirus work for sending telemetry to Red Canary?
Microsoft Defender for Endpoint (Formerly Defender ATP)
Microsoft Defender Antivirus is included in a standard Windows 10 installation. Defender Antivirus does not send telemetry and cannot be used to connect with Red Canary. Defender for Endpoint is offered from Microsoft separately and has to be installed on an endpoint in order for telemetry to be sent to Red Canary.
See How Red Canary integrates with Microsoft Defender for further info.