PowerShell scripts for Remediations

Članak
04/30/2024

This article includes sample scripts that customers can implement or use as templates to learn how to create their own. Use the information provided here to create script packages for Remediations.

Script descriptions

This table shows the script names, descriptions, detections, remediations, and configurable items. Script files whose names start with Detect are detection scripts. Remediation scripts start with Remediate. These scripts can be copied from the next section in this article.

Script name	Description
Check network certificates `Detect_Expired_Issuer_Certificates.ps1` `Remediate_Expired_Issuer_Certificates.ps1`	Detects certificates issued by a CA in either the Machine's or User's personal store that are expired, or near expiry. Specify the CA by changing the value for `$strMatch` in the detection script. Specify 0 for `$expiringDays` to find expired certificates, or specify another number of days to find certificates near expiry. Remediates by raising a toast notification to the user. Specify the `$Title` and `$msgText` values with the message title and text you want users to see. Notifies users of expired certificates that might need to be renewed. Run the script using the logged-on credentials: Yes
Clear stale certificates `Detect_Expired_User_Certificates.ps1` `Remediate_Expired_User_Certificates.ps1`	Detects expired certificates issued by a CA in the current user's personal store. Specify the CA by changing the value for `$certCN` in the detection script. Remediates by deleting expired certificates issued by a CA from the current user's personal store. Specify the CA by changing the value for `$certCN` in the remediation script. Finds and deletes expired certificates issued by a CA from the current user's personal store. Run the script using the logged-on credentials: Yes
Update stale Group Policies (built-in) `Detect_stale_Group_Policies.ps1` `Remediate_stale_GroupPolicies.ps1`	Detects if last Group Policy refresh is greater than `7 days` ago. This script package is included with Remediations, but a copy is provided if you want to change the threshold. Customize the seven day threshold by changing the value for `$numDays` in the detection script. Remediates by running `gpupdate /target:computer /force` and `gpupdate /target:user /force` Can help reduce network connectivity-related support calls when certificates and configurations are delivered via Group Policy. Run the script using the logged-on credentials: Yes

Check network certificates script package

This script package detects certificates issued by a CA in either the Machine's or User's personal store that are expired, or near expiry. The script remediates by raising a toast notification to the user.

Detect_Expired_Issuer_Certificates.ps1

#=============================================================================================================================
#
# Script Name:     Detect_Expired_Issuer_Certificates.ps1
# Description:     Detect expired certificates issued by "CN=<your CA here>" in either Machine
#                  or User certificate store
# Notes:           Change the value of the variable $strMatch from "CN=<your CA here>" to "CN=..."
#                  For testing purposes the value of the variable $expiringDays can be changed to a positive integer
#                  Don't change the $results variable
#
#=============================================================================================================================

# Define Variables
$results = @()
$expiringDays = 0
$strMatch = "CN=<your CA here>"

try
{
    $results = @(Get-ChildItem -Path Cert:\LocalMachine\My -Recurse -ExpiringInDays $expiringDays | where {$_.Issuer -match $strMatch})
    $results += @(Get-ChildItem -Path Cert:\CurrentUser\My -Recurse -ExpiringInDays $expiringDays | where {$_.Issuer -match $strMatch}) 
    if (($results -ne $null)){
        #Below necessary for Intune as of 10/2019 will only remediate Exit Code 1
        Write-Host "Match"
        Return $results.count
        exit 1
    }
    else{
        #No matching certificates, do not remediate
        Write-Host "No_Match"        
        exit 0
    }   
}
catch{
    $errMsg = $_.Exception.Message
    Write-Error $errMsg
    exit 1
}

Remediate_Expired_Issuer_Certificates.ps1

#=============================================================================================================================
#
# Script Name:     Remediate_Expired_Issuer_Certificates.ps1
# Description:     Raise a Toast Notification if expired certificates issued by "CN=..."
#                  to user or machine on the machine where detection script found them. No remediation action besides
#                  the Toast is taken.
# Notes:           Change the values of the variables $Title and $msgText
#
#=============================================================================================================================

## Raise toast to have user contact whoever is specified in the $msgText

# Define Variables
$delExpCert = 0
$Title = "Title"
$msgText = "message"

# Main script
[Windows.UI.Notifications.ToastNotificationManager, Windows.UI.Notifications, ContentType = WindowsRuntime] | Out-Null
[Windows.UI.Notifications.ToastNotification, Windows.UI.Notifications, ContentType = WindowsRuntime] | Out-Null
[Windows.Data.Xml.Dom.XmlDocument, Windows.Data.Xml.Dom.XmlDocument, ContentType = WindowsRuntime] | Out-Null

$APP_ID = '{1AC14E77-02E7-4E5D-B744-2EB1AE5198B7}\WindowsPowerShell\v1.0\powershell.exe'

$template = @"
<toast>
    <visual>
        <binding template="ToastText02">
            <text id="1">$Title</text>
            <text id="2">$msgText</text>
        </binding>
    </visual>
</toast>
"@

$xml = New-Object Windows.Data.Xml.Dom.XmlDocument
$xml.LoadXml($template)
$toast = New-Object Windows.UI.Notifications.ToastNotification $xml
[Windows.UI.Notifications.ToastNotificationManager]::CreateToastNotifier($APP_ID).Show($toast)

Clear stale certificates script package

This script package detects expired certificates issued by a CA in the current user's personal store. The script remediates by deleting expired certificates issued by a CA from the current user's personal store.

Detect_Expired_User_Certificates.ps1

#=============================================================================================================================
#
# Script Name:     Detect_Expired_User_Certificates.ps1
# Description:     Detect expired certificates issued by "CN=<your CA here>" to User
# Notes:           Change the value of the variable $certCN from "CN=<your CA here>" to "CN=...".
#                  Don't change $results
#
#=============================================================================================================================

# Define Variables
$results = 0
$certCN = "CN=<your CA here>"

try
{   
    $results = Get-ChildItem -Path Cert:\CurrentUser\My -Recurse -ExpiringInDays 0 | where {$_.Issuer -eq($certCN)}
    if (($results -ne $null)){
        #Below necessary for Intune as of 10/2019 will only remediate Exit Code 1
        Write-Host "Match"
        Return $results.count
        exit 1
    }
    else{
        Write-Host "No_Match"
        exit 0
    }    
}
catch{
    $errMsg = $_.Exception.Message
    Write-Error $errMsg
    exit 1
}

Remediate_Expired_User_Certificates.ps1

#=============================================================================================================================
#
# Script Name:     Remediate_Expired_User_Certificates.ps1
# Description:     Remove expired certificates issued by "CN=<your CA here>" to User
# Notes:           Change the value of the variable $certCN from "CN=<your CA here>" to "CN=..."
#
#=============================================================================================================================

# Define Variables
$certCN = "CN=<your CA here>"

try
{
    Get-ChildItem -Path cert:\CurrentUser -Recurse -ExpiringInDays 0 | where {$_.Issuer -eq($certCN)} | Remove-Item
    exit 0
}
catch{
    $errMsg = $_.Exception.Message
    Write-Error $errMsg
    exit 1
}

Update stale Group Policies script package

This script package is included with Remediations, but a copy is provided if you want to change the threshold.

This script package detects if last Group Policy refresh is greater than 7 days ago. The script remediates by running gpupdate /target:computer /force and gpupdate /target:user /force.

Detect_stale_Group_Policies.ps1

#=============================================================================================================================
#
# Script Name:     Detect_stale_Group_Policies.ps1
# Description:     Detect if Group Policy has been updated within number of days
# Notes:           Remediate if "Match", $lastGPUpdateDays default value of 7, change as appropriate
#
#=============================================================================================================================

# Define Variables

try {
    $gpResult = [datetime]::FromFileTime(([Int64] ((Get-ItemProperty -Path "Registry::HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Group Policy\State\Machine\Extension-List\{00000000-0000-0000-0000-000000000000}").startTimeHi) -shl 32) -bor ((Get-ItemProperty -Path "Registry::HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Group Policy\State\Machine\Extension-List\{00000000-0000-0000-0000-000000000000}").startTimeLo))
    $lastGPUpdateDate = Get-Date ($gpResult[0])
    [int]$lastGPUpdateDays = (New-TimeSpan -Start $lastGPUpdateDate -End (Get-Date)).Days
        
    if ($lastGPUpdateDays -gt 7){
        #Exit 1 for Intune. We want it to be within the last 7 days "Match" to remediate in SCCM
        Write-Host "Match"
        exit 1
    }
    else {
        #Exit 0 for Intune and "No_Match" for SCCM, only remediate "Match"
        Write-Host "No_Match"
        exit 0
    }
}
catch {
    $errMsg = $_.Exception.Message
    return $errMsg
    exit 1
}

Remediate_stale_GroupPolicies.ps1

#=============================================================================================================================
#
# Script Name:     Remediate_stale_GroupPolicies.ps1
# Description:     This script triggers Group Policy update
# Notes:           No variable substitution needed
#
#=============================================================================================================================

try {
    $compGPUpd = gpupdate /force
    $gpResult = [datetime]::FromFileTime(([Int64] ((Get-ItemProperty -Path "Registry::HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Group Policy\State\Machine\Extension-List\{00000000-0000-0000-0000-000000000000}").startTimeHi) -shl 32) -bor ((Get-ItemProperty -Path "Registry::HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Group Policy\State\Machine\Extension-List\{00000000-0000-0000-0000-000000000000}").startTimeLo))
    $lastGPUpdateDate = Get-Date ($gpResult[0])
    [int]$lastGPUpdateDays = (New-TimeSpan -Start $lastGPUpdateDate -End (Get-Date)).Days

    if ($lastGPUpdateDays -eq 0){
        Write-Host "gpupdate completed successfully"
        exit 0
    }
    else{
        Write-Host "gpupdate failed"
        }
}
catch{
    $errMsg = $_.Exception.Message
    return $errMsg
    exit 1
}

Next steps

For information about deploying script packages, see Remediations.