Twitter was unexpectedly catapulted to becoming a critical link to the uprising in Iran over the past week or two and millions are following tweets from the streets of Tehran. Unfortunately it also has been invaded by tweets with links to malware by Twitter spammers, according to this article. Because so many Twitter users like to watch the live feed of tweets on popular topics, spammers have decided to take advantage of all those watching. All a spammer has to do is include keywords within their tweet that relate to a popular topic on Twittter, and it will show up in the feed for that topic. Then, they simply include a link to a web page with malicious code. When a user following Twitter clicks on the link in the spammer's tweet, their computer becomes infected.
This post identifies some of the popular domains that Twitter spammers are using, and how to stay away from malicious tweets. Because so many of the URLs in tweets are shortened by URL shortening services, its important to remember that this list may not be comprehensive, and malicious links could be hiding in an otherwise safe looking link. It's important to remain vigilant when clicking on unknown links on sites like Twitter.