Facebook works with Websense to add phishing safety net

Users will see this notice if they are about to visit a potentially harmful website, giving them the option to go back to the previous page

Facebook have stepped up their battle against phishing and malware scammers by partnering with security firm Websense.

As of next week, users will be warned if they are about to be taken to a malicious website.

The social network has suffered to date as many of its 700 million users unwittingly click on dangerous links supposedly posted by their friends.

Such attacks usually trick users into sharing passwords or data.

Facebook already tells users if they are about to visit an external site, but the current set up makes no distinction between friendly and dangerous sites.

The new technology will present a warning screen whenever it suspects a page poses a threat to the users, giving details of the risk.

From here, users are encouraged to return to the previous page.

If they wish, users can continue to the intended page, albeit very much at their own risk.

'Profitable target'

Both Facebook and Websense will hope the extra measures will be enough to deter potential scammers from focusing their efforts on the network.

Scams regularly catch out hundreds of thousands of users at a time.

"There's over 700 million users on Facebook," Websense's Spencer Parker told the BBC.

"As a piece of real estate, it's extremely profitable to be targeted by malware writers."

The protection will be powered by Websense's "Threatseeker Cloud", a system which stores a database of known malicious URLs.

The system can also detect unknown dangerous URLs by assessing threats in real-time.

This means harmful URLs can be blocked even before they are known to the company - cutting off a key tactic used by phishers in which constantly changing URLs fool database-driven protection.

In addition, the system will "follow" links made using popular URL shorteners - such as bit.ly and ow.ly - to verify their safety.

Due to the nature of how we interact with our friends, Mr Parker says phishing attacks on Facebook are much harder to prevent than other commonly used techniques.

"One of the things with Facebook, of course, is that you have that element of trust in a social network. If one of your friends posts something, you automatically trust it more than if it just received as a spam email.

"As more of these 'friend in the middle' attacks happen, you start to trust your friends less."