Facebook is strengthening its security controls in an attempt to protect its 900 million users from spam and malicious content.
Facebook said Wednesday that it will work with Microsoft Corp. and with computer security firms Trend Micro Inc., Sophos, Symantec Corp. and Intel Corp.'s McAfee to provide safeguards on Facebook.
To do so, Facebook is expanding its blacklist system for blocking malicious Web links shared on the social network. And the security companies will offer free six-month trials of their antivirus software to Facebook users.
Facebook Inc. says less than 4 percent of the content shared through its social network is spam. That figure is much higher for email, though a lot of spam emails are filtered out even before they hit your spam folder.