- Reference
- Module:
- Defender
Updates the antimalware definitions on a computer.
Syntax
Update-MpSignature [-UpdateSource <UpdateSource>] [-CimSession <CimSession[]>] [-ThrottleLimit <Int32>] [-AsJob] [<CommonParameters>] Description
The Update-MpSignature cmdlet updates the antimalware definitions with the latest definitions available on an update server.
Examples
Example 1: Update signatures
PS C:\> Update-MpSignatureThis command updates the antimalware definitions.By default, the cmdlet uses the sources configured through SignatureFallbackOrder. If no signature fallback order is configured, the cmdlet uses the default update source.
Example 2: Update signatures from a specific source
PS C:\> Update-MpSignature -UpdateSource MicrosoftUpdateServerThis command updates the antimalware definitions from the Microsoft Update Server.
Parameters
-AsJob
Runs the cmdlet as a background job. Use this parameter to run commands that take a long time to complete.
The cmdlet immediately returns an object that represents the job and then displays the command prompt.You can continue to work in the session while the job completes.To manage the job, use the *-Job cmdlets.To get the job results, use the Receive-Job cmdlet.
For more information about Windows PowerShell background jobs, see about_Jobs.
| Type: | SwitchParameter |
| Position: | Named |
| Default value: | None |
| Required: | False |
| Accept pipeline input: | False |
| Accept wildcard characters: | False |
-CimSession
Runs the cmdlet in a remote session or on a remote computer.Enter a computer name or a session object, such as the output of a New-CimSession or Get-CimSession cmdlet.The default is the current session on the local computer.
| Type: | CimSession[] |
| Aliases: | Session |
| Position: | Named |
| Default value: | None |
| Required: | False |
| Accept pipeline input: | False |
| Accept wildcard characters: | False |
-ThrottleLimit
Specifies the maximum number of concurrent operations that can be established to run the cmdlet.If this parameter is omitted or a value of 0 is entered, then Windows PowerShell® calculates an optimum throttle limit for the cmdlet based on the number of CIM cmdlets that are running on the computer.The throttle limit applies only to the current cmdlet, not to the session or to the computer.
| Type: | Int32 |
| Position: | Named |
| Default value: | None |
| Required: | False |
| Accept pipeline input: | False |
| Accept wildcard characters: | False |
-UpdateSource
Specifies an update source.This cmdlet downloads updated definitions from the server you specify.If you do not specify this parameter, the cmdlet uses the sources configured through SignatureFallbackOrder. If no signature fallback order is configured, the cmdlet uses Microsoft Update Server, then Microsoft Malware Protection Center (MMPC) as an update source.The acceptable values for this parameter are:
- InternalDefinitionUpdateServer
- MicrosoftUpdateServer
- MMPC
- FileShares
If you specify the InternalDefinitionUpdateServer setting, the service checks for updates on the Windows Software Update Services (WSUS) server.
| Type: | UpdateSource |
| Accepted values: | InternalDefinitionUpdateServer, MicrosoftUpdateServer, MMPC, FileShares |
| Position: | Named |
| Default value: | None |
| Required: | False |
| Accept pipeline input: | False |
| Accept wildcard characters: | False |
