$p = Get-CimInstance Win32_Process -Filter "ProcessId=1876"
$p | Select-Object ProcessId,ParentProcessId,ExecutablePath,CommandLine
if ($p -and $p.ExecutablePath) {
Get-AuthenticodeSignature -FilePath $p.ExecutablePath |
Select-Object Status,@{Name="Signer";Expression={$_.SignerCertificate.Subject}}
}