Microsoft Defender for Business vs Sirius
Microsoft Defender for Business
microsoft.comSirius
opensecurity.comSide by side
| Figure | Microsoft Defender for Business | Sirius |
|---|---|---|
| Price from | $0.25/mo | Free |
| Free plan | — | Yes |
| Free trial | Yes | — |
| Open source | — | — |
| Web | — | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | — | Yes |
| iOS | Yes | — |
| Android | Yes | — |
| API | Yes | Yes |
| Self-hosted | — | Yes |
| Plans published | 4 | 2 |
| Spec score · Vulnerability Scanning Software | 8.8 (#4) | 7.9 (#13) |
| Headquarters | Redmond, Washington, United States | San Antonio, Texas |
| Purpose | Microsoft Defender for Business is an endpoint security solution for small and medium-sized businesses with up to 300 users that helps protect devices from ransomware, malware, phishing, and other threats. | Sirius is an open-source vulnerability scanner that combines network discovery, CVE detection, agent telemetry, and operator-driven triage. |
| Support | Microsoft's Defender for Business documentation provides a guide for getting help or contacting support. | Community support is available through Discord, GitHub Issues, and GitHub Discussions; the support page also describes enterprise priority support with dedicated channels and SLA guarantees. |
Plans
Microsoft Defender for Business
- Microsoft Defender for Business$3 a month
- Microsoft Entra Internet Access$5 a month
- Microsoft Entra Suite$12 a month
- Microsoft Defender for Business$3 a year
In their own words
Microsoft Defender for Business
Microsoft Defender for Business has no write-up on Specifiction yet; its figures are above.
Sirius
Sirius is an open-source vulnerability scanner for security teams that want operator control over discovery and triage. It combines network discovery, CVE detection, agent telemetry, and scanning through Nmap and Naabu. The Vulnerability Navigator provides severity groupings, CVSS-based filters, and export options; the Operator Console supports command execution, command history, and active-agent management. Dashboards show service health, infrastructure metrics, vulnerability trends, and centralized logs. Sirius can run in production or development mode through Docker Compose. Its listed minimum requirements are Docker Engine 20.10.0+ with Compose V2, 4 GB RAM, and 10 GB of free disk space. Supported host systems are Linux, macOS, and Windows through WSL2. REST endpoints on port 9001 use an API key, with documentation linking to an API reference and Go SDK. The Sirius Scan plan is free for self-hosted Docker use. Community support is available through Discord, GitHub Issues, and GitHub Discussions; the support page also describes enterprise priority support.