Quick and dirty script to generate a random IMEI from an existing one.

Generate-IMEI.ps1

<# Takes an IMEI number, randomizes the SNR (unique identifier), calculates the check digit using Luhn algorithm, and returns the resulting IMEI.
#>
function Generate-IMEI([string] $seed) {
    #generate random SNR
    $str = ($seed.substring(0,8)+ [string](Get-Random -max 999999 -min 0) + $seed[14])
    $ca = $str.ToCharArray()
    $sum = 0 
    #calculate check digit
    for($i=0; $i -lt $ca.length-1; $i++) {
        $digit = [int]([string]$ca[$i])
        if(($i % 2) -ne 0) { 
            $digit = $digit*2 
        }
        #sum up digits, ie 32 => 3+2 = 5
        [int[]](($digit -split '') -ne '') | %{$sum += $_};
    }
    return ($str.substring(0,14)+([math]::ceiling($sum/10)*10 - $sum))
}