A "worrying number" of Facebook users are sharing a link to a malware-laden fake CNN news page reporting the U.S. has attacked Iran and Saudi Arabia, security firm Sophos said Friday.

If users who follow the link then click to play what purports to be video coverage of the attack, they are prompted to update their Adobe Flash player with a pop-up window that looks very much like the real thing. Those who accept the prompt unwittingly install malware on their computers....