$checkShadow is $null when no shadow copies exist

[nmanzi]

On at least Windows 10 20H2 (19042.1110), Get-WmiObject Win32_ShadowStorage returns $null when shadow copies are not configured and none exist.

This lead to $fixed = $false, when in fact the issue is fixed.

Recommend updating to the following:

#check shadow
if ($vulnerable -eq $true) {
    $checkShadow = Get-WmiObject Win32_ShadowStorage -Property UsedSpace | Select-Object -ExpandProperty UsedSpace
    if ((0 -eq $checkShadow) -or ($null -eq $checkShadow)) {
        $shadowSucces = $true
        Write-Host "Successfully deleted old volume shadow copies."
    }
    else {
        $shadowSucces = $false
        write-host "Shadow deletion failed. Security software may be blocking this action or check running permissions."
    }
}

HiveNightmare/Mitigation.ps1

Line 40 in 0428053

if (0 -eq $checkShadow) {

[GossiTheDog]

Ooops, good shout, this will need fixing.