This is how you scan a file or folder manually with Defender Antivirus

[Windows Central]

Do you have a suspicious file? If so, you can scan it for malware manually using Microsoft Defender Antivirus on Windows 10 – here are three ways to complete the task.
Microsoft Defender Antivirus is the anti-malware application that comes integrated with every installation of Windows 10. Out of the box, it provides robust real-time protection against viruses, ransomware, spyware, and many other types of malware and hackers.

Full story from the WindowsCentral blog...