A new malware threat has surfaced on Twitter using goo.gl shortlinks, the wording of the initial threat is:
Just found the easiest way to track who follows and unfollows you – http://goo.gl/kLE5M
If you click the link it appears the worm is compromising your Twitter account and using it to resend the message. Twitter are aware of the problem and hopefully blocking it.
If you’re unsure of the shortlink you’re clicking on, put it through Sucuri first which will show you the final URL you’re going to be directed to, this will give you better understanding if the link is a threat or not.