Immutable. This exact content is served forever at /api/v1/blob/2e4c6c18475fb233.
--- name: defender-quickscan description: "Windows Defender: scans, threat history, signatures (PowerShell)" category: windows version: 1.0.0 platform: windows tags: defender, antivirus, security, scan, threat, malware, windows, powershell license: Apache-2.0 --- # Defender Quick Scan Trigger Windows Defender antivirus scans, inspect threat history, update virus definitions, and check real-time protection status — all via PowerShell cmdlets. ## When to Use - User wants to run a quick or full antivirus scan - User asks about recent threats detected by Defender - User wants to check if real-time protection is enabled - User needs to update virus/malware signatures - User wants to know the current Defender protection status ## How to Use ### Check Windows Defender status ```powershell Get-MpComputerStatus | Select-Object AMServiceEnabled, AntispywareEnabled, AntivirusEnabled, RealTimeProtectionEnabled, AntispywareSignatureAge, AntivirusSignatureAge, QuickScanAge ``` ### Run a quick or full scan ```powershell Start-MpScan -ScanType QuickScan # fast scan of likely threat locations Start-MpScan -ScanType FullScan # thorough scan of all files (30-60 min) ``` ### Scan a specific file or folder ```powershell Start-MpScan -ScanType CustomScan -ScanPath "C:\Users\shiva\Downloads" ``` ### Update virus definitions ```powershell Update-MpSignature ``` ### View threat detection history ```powershell Get-MpThreatDetection | Select-Object ThreatID, ActionSuccess, DetectionSourceTypeID, Resources, InitialDetectionTime | Sort-Object InitialDetectionTime -Descending | Select-Object -First 10 ``` ### View active threats ```powershell Get-MpThreat | Select-Object ThreatID, ThreatName, SeverityID, CategoryID, IsActive, Resources ``` ### Remove a detected threat ```powershell Remove-MpThreat -ThreatID 12345 ``` ### Check exclusion list ```powershell (Get-MpPreference).ExclusionPath (Get-MpPreference).ExclusionExtension ``` ### Add a scan exclusion (path) ```powershell Add-MpPreference -ExclusionPath "C:\DevTools\node_modules" ``` ## Examples **"Scan my Downloads folder for threats"** → `Start-MpScan -ScanType CustomScan -ScanPath "$env:USERPROFILE\Downloads"` — Defender scans the folder and logs any detections. **"Are my virus definitions up to date?"** → `Get-MpComputerStatus | Select-Object AntivirusSignatureAge, AntivirusSignatureLastUpdated` — signature age of 0 means updated today. **"Show me the last 5 threats Defender found"** → `Get-MpThreatDetection | Sort-Object InitialDetectionTime -Descending | Select-Object -First 5` ## Cautions - Full scans can take 30-60 minutes and consume significant CPU/IO — warn the user before running - `Start-MpScan` requires Windows Defender to be the active antivirus — third-party AV may disable these cmdlets - Removing a threat with `Remove-MpThreat` is permanent; confirm with the user before executing - Adding exclusions reduces protection coverage — only exclude paths you're certain are safe