Open Event Viewer. In the console tree, expand Applications and Services Logs, then Microsoft, then Windows, then Windows Defender Antivirus. Double-click on Operational.
All is stored in these folders %ProgramData%\Microsoft\Windows Defender\Scans %ProgramData%\Microsoft\Windows Defender\Scans\History\ %ProgramData%\Microsoft\Windows Defender\Scans\History\Store\