How do spammers use fake URL-shortening services? Shortened links created by spammers on the fake URL-shortening sites actually aren’t typically included directly in spam messages. Instead, the spam emails contain shortened URLs created on legitimate URL-shortening sites. These shortened URLs lead to a shortened-URL on the spammer's fake URL-shortening Web site, which in turn redirects to the spammer's own Web site.
The report notes that many new domains were registered several months before they were used, potentially as a means to evade detection by legitimate URL-shortening services since the age of the domain may be used as an indicator of legitimacy making it more difficult for the genuine shortening services to identify potential abuse.