Facebook became the world’s largest social network by giving users a cleaner more intimate way to connect with friends and family. Yet social networking spam is now a problem for three out of four Facebook users according to an international survey of Facebook users committed by F-Secure.

78% think spam is a problem on the site, 49% report that they at least frequently see something in their newsfeed that they consider spam.

Internet users now spend more time on social networks than they do on email. Recognizing this, spammers have adapted their methods to fit the medium.

“A lot of this spam is cost-per-action spam,” says F-Secure Security Advisor Sean Sullivan. “In the old days, adware toolbars were the product, and they had direct affiliates. Now with social networking spam, I’m seeing affiliate networks acting as the middlemen for the product or brand, which allows localization across the globe.”

The growth in social networking spam comes both from spam applications and fake profiles.

The applications push viral concepts like the Facebook “Dislike” button, which was tried by 12% Facebook users, or the ability to see whom has viewed your profile, tried by 20%. Once a user activates a spam application it instantly becomes shared with all of their friends, possibly spreading a scam.

The fake profiles usually employ a profile picture that presents an alluring young female. Often the profiles feature frequent updates are build up large friends lists through months of activity before they begin spewing spam, often for adult sites. “There’s serious time involved in gathering up 4,000 friends,” says Sullivan.

While spam may diminish users’ experience on the site, the majority of Facebook users still feel comfortable. 77% said they feel safe on the site at least most of the time. When it comes to security, users worry most about protecting their financial details and their personal reputation or brand. 29% are most concerned about identity theft while 28% are most troubled by the thought their Facebook account being hacked.

This suggests that users closely connect their Facebook identity with their real world identity. This connection along with a clean interface and a lack of spam helped Facebook surge past competitors like MySpace.

Facebook has recently taken new steps to eliminate spam, including legal action against alleged spammers and site enhancements like the ability to report comments as spam and a spam filter for business pages.

There are more steps Facebook can take to remove the fake profiles that produce more and more spam. “You cannot easily report a profile as spam,” says Sullivan. “Using photo recognition to identify fake profiles could also be helpful, as many of the profile pictures are used again and again.”

The best way users can reduce the Facebook spam they encounter is by only friending people they know and trust. “You create your network,” Sullivan says. “By keeping the spammers out, you protect your friends and family.”