The app lures people into installing it with the promise that it will reveal which friend of theirs has a secret crush on them. After installation, the user/victim also has to ask a minimum of five other Facebook users to install the application in order to get the much-desired result.

However, they have a long wait ahead of them. The results won’t become available; instead, users are directed to another site which invites them to download various applications that will display annoying pop-up advertising. With around 50,000 Facebook users already rumored to have installed the Secret Crush app, someone must be seriously cashing in.

"Whoever wrote this Secret Crush application is cashing-in big time, by encouraging people to download the adware. As an affiliate for the people displaying the nuisance pop-up adverts, they are getting paid for each successful installation," said Graham Cluley, senior technology consultant for Sophos. "Facebook users must show greater discretion about how they use the site, and which applications they install. These third party widgets are not written by Facebook, and can mean that you are carelessly sharing your personal information with strangers or risking your computer’s security."

Recently, Facebook has removed Secret Crush from its search results.