A worm linked to a new phishing scam is spreading via messages on Twitter.

Already compromised accounts are sending direct messages to users including a link to a video clip, like this:

"rofl this you on here? videos.twitter.secure-logins01.com"

Users who follow the link are invited to submit their login credentials via a counterfeit Twitter login page (screenshot via Sophos here: http://www.sophos.com/blogs/gc/g/2009/09/24/rofl-twitter-phishing-attack-laughing-matter ).
In the process they surrender control of their micro-blogging account to hackers, who use the access to send out a fresh round of phishing lures.

This is far from the first time miscreants have launched a phishing attack that targets Twitterusers. Previous assaults along the same lines claimed to link to a "funny picture" of the victim: http://www.sophos.com/blogs/gc/g/2009/01/04/phishing-scam-spreads-twitter
As with the latest attack the phishing lures came in direct messages from someone an intended mark was likely to know.

Users hit by the latest scam are advised to change their password, if possible. If that fails micro-bloggers will need to contact Twitter support.

Hacking into Twitter accounts may be an end in itself or part of something bigger. Cybercrooks are also interested in harvesting Twitter login details because many consumers use the same password across multiple sites, so that access to Twitter grants access to webmail or other even more sensitive accounts.

(Register)