Is Windows Defender Safe?
Windows Defender — Nerq Trust Score 65.2/100 (B- grade). Based on analysis of 2 trust dimensions, it is generally safe but has some concerns. Last updated: 2026-05-08.
Use Windows Defender with some caution. Windows Defender is a antivirus software (now comparable to paid solutions) with a Nerq Trust Score of 65.2/100 (B-), based on 3 independent data dimensions. Below the recommended threshold of 70. Security: 90/100. Popularity: 100/100. Data sourced from multiple public sources including package registries, GitHub, NVD, OSV.dev, and OpenSSF Scorecard. Last updated: 2026-04-02. Machine-readable data (JSON).
Is Windows Defender safe?
CAUTION — Windows Defender has a Nerq Trust Score of 65.2/100 (B-). It has moderate trust signals but shows some areas of concern that warrant attention. Suitable for development use — review security and maintenance signals before production deployment.
What is Windows Defender's trust score?
Windows Defender has a Nerq Trust Score of 65.2/100, earning a B- grade. This score is based on 2 independently measured dimensions including security, maintenance, and community adoption.
What are the key security findings for Windows Defender?
Windows Defender's strongest signal is popularity at 100/100. No known vulnerabilities have been detected. It has not yet reached the Nerq Verified threshold of 70+.
What is Windows Defender and who maintains it?
| Author | Unknown |
| Category | Antivirus |
| Source | N/A |
Antivirus Assessment
Independent Lab Results (AV-TEST)
Windows Defender scored 6.0/6 on protection and 5.5/6 on performance in AV-TEST independent testing. Perfect protection score. Slightly higher system impact than top performers.
Security Track Record
Windows Defender has no known major security incidents or privacy scandals.
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Safety Guide: Windows Defender
What is Windows Defender?
Windows Defender is a antivirus software — Microsoft Defender (formerly Windows Defender) is the built-in antivirus for Windows 10 and 11. Free, no installation required, auto-updates via Windows Update. AV-TEST score: 6/6 protection, 5.5/6 pe.
How to Verify Safety
Check AV-TEST lab results. Review incident history and privacy policy.
You can also check the trust score via API: GET /v1/preflight?target=Windows Defender
Key Safety Concerns for antivirus software
When evaluating any antivirus software, watch for: detection rate, system impact, privacy practices, jurisdiction.
Trust Assessment
Windows Defender has a Nerq Trust Score of 65/100 (B-) and has not yet reached Nerq trust threshold (70+). This score is based on automated analysis of security, maintenance, community, and quality signals.
Key Takeaways
- Windows Defender has a Trust Score of 65/100 (B-).
- Review carefully before use — below trust threshold.
- Always verify independently using the Nerq API.
Detailed Score Analysis
| Dimension | Score |
|---|---|
| Security | 90/100 |
| Maintenance | 50/100 |
| Popularity | 100/100 |
| Quality | 50/100 |
| Community | 35/100 |
Based on 5 dimensions. Data from multiple public sources including package registries, GitHub, NVD, OSV.dev, and OpenSSF Scorecard.
What data does Windows Defender collect?
Windows Defender has a privacy score of 65/100. Review the documentation and privacy policy for data handling details.
Full analysis: Windows Defender Privacy Report · Privacy review
Is Windows Defender secure?
Security score: 90/100. This meets the recommended security threshold for production use.
Nerq monitors this entity against NVD, OSV.dev, and registry-specific vulnerability databases for ongoing security assessment.
Full analysis: Windows Defender Security Report
How we calculated this score
Windows Defender's trust score of 65.2/100 (B-) is computed from multiple public sources including package registries, GitHub, NVD, OSV.dev, and OpenSSF Scorecard. The score reflects 5 independent dimensions: security (90/100), maintenance (50/100), popularity (100/100), quality (50/100), community (35/100). Each dimension is weighted equally to produce the composite trust score.
Nerq analyzes over 7.5 million entities across 26 registries using the same methodology, enabling direct cross-entity comparison. Scores are updated continuously as new data becomes available.
This page was last reviewed on May 08, 2026. Data version: 0.0.
Full methodology documentation · Machine-readable data (JSON API)
Frequently Asked Questions
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Disclaimer: Nerq trust scores are automated assessments based on publicly available signals. They are not endorsements or guarantees. Always conduct your own due diligence.