As the date of the shutdown of the interim systems that allow computers infected by the DNSChanger Trojan to connect to the Internet draws near,
Facebook has joined Google in sending out warnings to its infected users:
"Earlier this year, Facebook joined the clean up effort by participating in the DNSChanger Working Group, which is comprised of computer security experts from the public, private, and academic sectors," says Facebook. "As a result of our work with the group, Facebook is now able to notify users likely infected with DNSChanger malware and direct them to instructions on how to clean their computer or networks."
So please do not surprise if you get such information when you try to open your facebook.
You need to get rid of the dangerous Trojan virus immediately.