Update-MpSignature

Module:

Defender

Updates the antimalware definitions on a computer.

Syntax

Update-MpSignature
      [-AsJob]
      [-CimSession <CimSession[]>]
      [-ThrottleLimit <Int32>]
      [-UpdateSource <UpdateSource>]
      [<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-MpSignature

This 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 MicrosoftUpdateServer

This 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