Porn spam is emerging as a growing issues on social networking sites according to security outfit, BitDefender.

Recent research by the company shows that a sizable 15 per cent of Twitter traffic is unwanted porn, while seven per cent of Facebook traffic, and 10 per cent of Myspace traffic, is made of porn spam.

According to BitDefender, spammers have taken note of the switch to social networking and micro-blogging Web sites and are changing their tactics.

On Twitter, this is taking the form of porn spammers registering accounts, posting provocative images as their avatars, follow unsuspecting Twitter users and sending shortened URLs that link to pornographic material, the company’s senior anti-spam and anti-phishing researcher, Alexandru Catalin Cosoi said.

Spammers are also targeting users through links that facilitate the connection for downloading of malware. The malware can be activated at the point of infection then wait dormant for instructions to activate at a later date or hide until activated by a set of keywords, according to the company.

Senior Director for APAC Marketing at MessageLabs, Andrew Antal, said porn spam wasn’t new, but the range of techniques being used by hackers continued to evolve.

“Some of these social networking sites have softer privacy/security regulations that makes it easier to access email address books making it easier for the bad guys to launch spam runs,” he said.

In a further sign of the need for improved security controls on social media Web sites, Twitter users are reporting that they are being virally spammed by the game application, Mobster World.

The application, which lets users ‘start a mob family, recruit your friends, and rule the Twitter UnderWorld!’, automatically sends an invitation to play the game to every contacts in a user’s Twitter account.

To prevent it happening, users must scroll down, highlight dark grey text on a black background and squint to find that they need to click a small link on the game’s homepage.

This opt-out, rather than opt-in, approach has raised the ire of several Twitter users.

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