It appears that a worm has hit Twitter-the tweet will say “Best Video” with a link to “http://juste.ru.” If you see this in a tweet, do not click on the link. It’s unclear exactly how the worm is spreading. But from the look of Tweets about the virus, if you click on the link, you account could be compromised and spammed.
It is not good especially for those using it as a social marketing..
Twitter update status
More info at Techcrunch