Twitter has quietly started using a Google blacklist of suspected phishing and malware pages to filter malicious URLs leading to known malware sites.
Twitter hasn't announced it, but F-Secure's chief research officer Mikko Hypponen revealed how it was starting to filter tweets that linked to known malware sites.
According to his blog posting, users are given a warning message when they attempt to click on a link that leads to a blacklisted site.
He later confirmed - on Twitter - that the microblogging site was using Google Safe Browsing API, an experimental API that allows client applications to check URLs against an updated Google blacklist.
Twitter has become a bigger target for hackers taking advantage of its explosion in popularity.
This Easter, Twitter suffered four separate worm attacks that encouraged users to click on a link which infected them and made them automatically send out messages to friends with the same link.
Twitter has not replied to request for comment by time of writing.
