Microsoft Defender (built-in)Scan a Windows computer for malware and manage its built-in security protection.
Included with Windows
Passwords & security
ClamAV
Free optionOpen sourceLocal
Scan files and email attachments for malware using local antivirus tools.
What you can use it for
Scan files and email attachments for malware using local antivirus tools.
- Covers the core use case of Malwarebytes without a subscription.
- 7.4k GitHub stars, GPL-2.0, last commit 2026-08-27
Workflow coverage and comparison notes
Open-source antivirus engine for detecting trojans, viruses, malware and malicious threats.
Before you switch
No real-time GUI by default
Alternatives to these paid apps
Each comparison covers the workflow described above, rather than every paid feature.
More for the same workflow
See alternatives →Microsoft Defender (built-in)