Facebook users are once again targeted with a rogue app / survey scam combo.

The lure is a free McDonald's $100 gift card:

Users who want to get the prize are first asked to install a rogue app that is able to post messages on their Timeline in order to trick other victims into participating.

Then they are asked to either fill out some online surveys (complete with their personal information), download dubious toolbars or potentially malicious software, or share their mobile phone number and inadvertently sign up for pricy services.

"The scammers who create these bogus promotions will earn commissions via suspect affiliate marketing schemes each and every time a victim completes an offer or participates in a survey," Hoax-Slayer explains.

"Victims may also be faced with large phone bills for unwanted mobile phone services and, because they have provided name and contact details, they may be inundated with unwanted promotional emails, phone calls and junk mail."

It goes without saying that the victims will never receive the free gift card.