use Digest::SHA qw/sha256/;
use Encode qw/encode/;

$seed = 'DDFF5D36-F14D-495D-BAA6-3688786D6CFA';
$string = '123456789';

$target = '57392CD6A5192B6185C5999EB23D240BB7CEFD26E377D904F6FEF262ED176F97';

$encoded = encode('UCS-2LE', $seed.$string);
$sha256 = uc(unpack("H*", sha256($encoded)));

print "$targetn$sha256n";

HASHBYTES('SHA_256', 'DDFF5D36-F14D-495D-BAA6-3688786D6CFA123456789')