Defensio supplies a free tool you can use to stop hackers from posting viral web links on your Facebook wall.

You'll still have to be cautious about clicking on infectious links arriving in Facebook messages from friends or in Twitter microblogs. Such tainted links, which instantly pull your computer into a botnet, may not be coming from your trusted acquaintance, as we described in this story.

But by signing up for a Defensio account here, you can at least protect against bad guys littering your Facebook wall with infectious links. Defensio will also protect your personal blog specifically by blocking viral links from comments to your postings, another way bad guys can take control of your PC, as they did last fall exploiting the hype surrounding the release of Twilight, the vampire movie.

"Unfortunately, with the increased adoption of social networks by both individual users and corporations, the threat potentially has also escalated," said Carl Mercier, Director, Software Development, Websense. "With the Defensio application for Facebook, businesses and individual users can now protect their Facebook walls from malicious links, inappropriate content and comment spam."

By Byron Acohido