A whopping 20 percent of all Facebook users are active targets of malware through malicious posts, a study has revealed.

The shocking finding was made by BitDefender, a security software maker, which gleaned data from a Facebook application called Safego. The data point to how malwares are easily using the dominant social network for their malicious purposes, the study says.

It works when you click on one of your friends' news feeds. The malware then hijacks your account, and the same post is then posted on your friends' walls. The users targeted are totally unaware of the feed being posted on their friends' walls.

In this way various malicious posts have appeared as news feed across 20 percent of FB users' walls. It is spreading fast as most users are unaware of this situation.

The numbers were derived from Safego's analysis of news feed items viewed by 14,000 Facebook users who have installed the app.

Over 60 percent of attacks come from notifications from malicious third-party applications on Facebook's developer platform, the study found.

Within that, the most popular subset of attack apps (21.5 percent of total kinds of malware) were those that claim to perform a function that Facebook normally prohibits, like seeing who has viewed your profile and who has unfriended you.

As much as 15.4 percent of spam lures users with bonus items for Facebook games like free items in FarmVille, while 11.2 percent offer bonus Facebook features like free backgrounds and dislike buttons”.

The study found 7.1 percent of spam promises new versions of well-known gaming titles like World of Warcraft; 5.4 percent claim to give away free cell phones; and 1.3 percent claim to offer a way to watch movies for free online.

Beyond app attacks, BitDefender found that an additional 16 percent of malware viewed on Facebook entices users to watch some kind of shocking video.

The BitDefender app only analyzed what's visible in users' news feeds.