Facebook currently has 4 virus attacks. Inasmuch as the site owners are working hard clear these off the site, they still persist in various forms. These attacks can get your Facebook account hacked hence making you vulnerable. There are a few preventive measures you can take to secure yourself.
Below are some precautionary measures you can take
1) :- If you get a notice of a PHOTO TAG from people alien to you, do not open it directly. (Visit your timeline and see the thumbnail instead)
2) :- If you get a notification that a friend reported you for offensive behavior etc.. Do not open it directly.
3) :- Do not click or open links such as “99% of People can not watch this for more the 15 Sec”.
4) :- Do not click or open any messages from your friends via chat saying “click this link to/for ………”
It is better to ignore such. Purported leaked celebrity sex tapes etc. can be dangerous when clicked.
5) Change your password often
Share this info and Help your friends. Be Safe..!