how it works? According to mashable.com it malware links comes with normal tweets and and only affect you if you click on any of these links.
Beware “Twitterbest” and “Zasaden” in Twitter Search
Do not click on any of the linkes with these keywords.
If you click it will take you to a page that prompt you to upgrade the flash plug in and if you agree to download it the software install it self and then a error message saying there is a virus in your computer and need to download a Antivirus called "Fast-anti-virus-2009" for $89. (Goal of the malware)
Do not click on any of the links with these keywords “Twitterbest” and “Zasaden”.
Do not install any software or upgrade any drivers that pop up from any of the links.
It will be a really hard hard task to track the links as liks can be hidden using tools that use to shorten the urls (commonly use in twitter).
Also twitter shows the real time trending topics and that allows the attackers to target the most number of users at that time. Imagine if Google started to display real time trending search will create a big mess.