Shortened URL Spam Increases
The tendency of spammers to use shortened URLs to evade detection has gone from last year's clever exploit to this year's mainstream tactic, MessageLabs has reported.
In the second quarter of 2009, emails using shortened URLs exceeded 1 in 200 emails only once, the company's July 2010 Intelligence report notes.
During the same period this year, its figures showed that this threshold had been breached on 43 days. On 10 of these days, the volume of shortened hyperlinks accounted for five percent of all the spam measured by the company. The main recent culprit has been the Storm botnet, which spewed 11.8 percent of all the spam using the shortened URLs in the second quarter.