Twitter was yesterday attacked by a worm – Stack Daily worm which was all caused by a 17 year old kid who accepted that he was responsible for everything that happened yesterday. But it was nothing when compared to the game played today by the same kid?
Today, many accounts were affected by this worm and it posted many weird messages. One of the examples is as in my friends’ account in the image below -
It was said that whenever a person visits the attacked users profile, he too gets infected and the tweets get automatically posted.
I first changed my password to keep myself safe, as i had also visited few affected profiles. And actually, i am totally safe 
So here is what you can do -
1. Change your password as many claim to be safe/ or got rid of the worm when they changed the password.
2. As my friend Mohnish explains here -
Use NoScript Addon for Firefox and block the domains: uuuq.com, ireel.com
Then clear your cache. This would totally block the worm from entering into your account.
Resetting the password can help in both preventing from being attacked, and if already attacked, then get red of the worm. Also, if you are able to, then you can stay away from twitter and not visit any profiles or twitter pages until the twitter guys tell you that the issue is completely resolved.
Nice Info
Also refreshing your twitter settings would help you get rid of the worm if affected.