sign_all_powershell_script.ps1

<#
If you have UnknownError recreate script file with notepad.
This script must be signed first by
    Set-AuthenticodeSignature -FilePath "PATH_TO_THIS_SCRIPT" -Certificate (Get-PfxCertificate "PATH_TO_CERT")
or just change ExecutionPolicy.
#>
function sign_cert($file) {
    $certpath = "INSERT_PATH_TO_CERT"
    $certpass = "INSERT_PASS_FOR_CERT"
    $cert = New-Object System.Security.Cryptography.X509Certificates.X509Certificate2($certpath, $certpass)
    Set-AuthenticodeSignature -FilePath $file -Certificate $cert
}

$scriptfolder = Get-ChildItem "INSERT_FOLDER_WITH_SCRIPTS"

foreach ($item in $scriptfolder) {
    sign_cert($item.FullName)
}