Wildcard certificate from Comodo.
http://www.positivessl.com/ssl-certificate-positivessl_wildcard.php
SSL Certificates · Wildcard
Get access to data on 12,532,122 websites that are Comodo PositiveSSL Wildcard Customers. We know of 1,537,458 live websites using Comodo PositiveSSL Wildcard and an additional 10,994,664 sites that used Comodo PositiveSSL Wildcard historically and 652,057 websites in the United States.
Get a list of 12,532,122 websites using Comodo PositiveSSL Wildcard which includes location information, hosting data, contact details, 1,537,458 currently live websites and an additional 355,526 domains that redirect to sites in this list. 10,994,664 sites that used this technology previously and 652,057 websites in the United States currently using Comodo PositiveSSL Wildcard.