Malicious links are filtered at Twitter. Is it any safer now to tweet?

After a long period of tolerance to malware links on the site Twitter has started filtering web addresses to known malicious destinations. The move was not announced yet by the company, instead it was noticed by security researchers on Monday.

The introduction of the filtering comes as Twitter has been heavily hit by worms, spam and account hijacking attacks over recent weeks. The widespread use of URL shortening in Twitter messages (which can be no longer than 140 characters) makes it easy to hide the true destination of links.

Thus, the shield works this way. When an internet surfer tries to follow a link to a malicious destination from Twitter the system serves him/her up with a warning message according to Mikko Hypponen of F-Secure.

Meantime, Costin Raiu, a security researcher at Kaspersky Lab, notes that apparently Twitter deploys Google's Safe Browsing API. "It won't catch everything but is definitively a step forward," he adds.