Facebook users are continuously being hit by spam that claim to offer Free meal, Free Mobile Recharge, Some Nude Content or they may offer Free Money. Once you click on such links you are automatically taken to some inappropriate website. Sometimes it takes you to some Facebook application which asks you to allow to access your Facebook account.
How Does a Spam Spread?
1) Malware(Malicious software that harms your system) infects your friends computer
Secretly giving spammer control over Facebook or Twitter accounts
2) The spammer posts a message on your friend's Facebook profile, offering the same things.
3) You click on those links and you are taken to a website that sometimes instructs to download some stuff to view the content, or if they offered you a free coupon, they will tell you to download that coupon.
4) The malware infects your computer and lets spammer post the offer on your Facebook profile, repeating the same cycle with your Facebook friends.
Trying to Stop it ?
1) Individuals have to uninstall the Malware from their web browsers, or run anti-virus software that removes it.
2) Users should mark such messages as spam, alerting Facebook's site-integrity team. Facebook filters out messages that include the link.
(NEVER CLICK ON SUCH LINKS TO AVOID THE HASSLE)
3) Server hosting the Malware terminates the link. But the spammers quickly adapt their strategies, which causes the cat-and-mouse game to start all over again. They again put their Malware to another server, and start spamming.