$combined_file   = "C:\test\3.jpg"
$output_location = "C:\test\"

#Magic string to search for, example is taken from
#https://en.wikipedia.org/wiki/List_of_file_signatures as jpg example
$magic_sequence_of_bytes = "FF D8 FF E0 00 10 4A 46 49 46 00 01"
$ext = "jpg"

$byte_array_of_combined_file = [System.IO.File]::ReadAllBytes($combined_file)
$byte_start_offset = @()

$ar = $magic_sequence_of_bytes.Split(" ")
$findindex = 0;

for ($i = 0 ; $i -lt $byte_array_of_combined_file.Length; $i++)
{
   $v = '{0:X2}' -f $byte_array_of_combined_file[$i]
   if ($v -eq $ar[$findindex])
   {
      if ($findindex -eq $ar.Count-1)
      {
         Write-Host "Found string magic!" -ForegroundColor Green
         $pos = $i - ($ar.Count-1)
         write-host "$magic_sequence_of_bytes starts at offset" $pos
         $byte_start_offset +=$pos
      }
      $findindex=$findindex+1
   }
   else
   {
      $findindex = 0
   }
}

for ($f=0; $f -lt $byte_start_offset.Count; $f++)
{
   $filenameout = "$output_location$f-recreated.$ext"

   if ($f -eq $byte_start_offset.Count -1)
   {
       $s = $byte_start_offset[$f]
       $e = $byte_array_of_combined_file.Length
   }
   else
   {
       $s =  $byte_start_offset[$f]
       $e = ($byte_start_offset[$f+1] -1)
   }
   write-host  "Creating file:" $filenameout
   [System.IO.File]::WriteAllBytes($filenameout, $byte_array_of_combined_file[$s..$e])
}