CYBERSPACE – If you build it, porn will come. That’s the message digital security firms are spreading these days.Once upon a time, porn spam overflowed email inboxes. Today — thanks in part to anti-spam laws and domain blacklisting, but mostly to spam’s ineffectiveness as a marketing tool — inboxes are a channel of last resort. Instead, spammers have moved on to the hottest trend of the moment: social networking sites.

According to Alexandru Catalin Cosoi, a Bucharest-based anti-spam and anti-phishing researcher for security firm BitDefender, as much as 15 percent of tweets on micro-blogging site Twitter are porn spam. MySpace and Facebook are close behind with 10 percent and seven percent of their traffic related to porn, he told The Canadian Press. Cosoi hasn’t narrowed down the percentage of porn spam on voice-over-internet-protocol service Skype, but he reckons it’s significant judging by the number of “sexy girls” using one instant-messaging client or another to send blanket come-ons to Skype users.

Porn spam has been around nearly as long as the internet has resided in the public realm, according to Fiaaz Walji, an Ottawa-based manager for Web-security firm Websense. It’s not likely to disappear anytime soon. And the sexually suggestive, if not always explicit, nature of the messages isn’t the real problem, anyway, he warned. What should concern those willing to take a chance by clicking on links in porn spam is something much more insidious: identity and data theft.

“Really, it’s used to garner or capture a lot of users and steal their data,” he told TCP.

The promise of salacious video frequently is used to lure consumers into downloading malware. At least half of the porn spam on social networking sites links to malicious content, Walji said.

“The malware could be activated at that very moment, or it could sit dormant on your computer until it gets activated by a bot network of some sort, or it could get activated by key words,” he told TCP.

Corporal Louis Robertson, a Royal Canadian Mounted Police officer who works in criminal intelligence for the Canadian Anti-Fraud Centre-Phonebusters in North Bay, Ont., said another porn-spam-related scam is on the RCMP’s radar, as well. Increasingly, social-networking sites are connecting blackmailers with prospective victims. The scammers threaten to reveal “embarrassing or damaging” information, personal data or photos online unless victims pay them.

Twitter has begun to take action to stem the rising tide of porn spam on its pages. The service advises users to block suspected spammers or send to Twitter headquarters a direct message containing the user names associated with suspicious profiles. The site’s terms of service prohibit “obscene or pornographic images,” but Twitter has a long way to go to eradicate “twammers,” according to users.

“If you’re going to spam me with porn, at least have the decency to airbrush out your stretch marks,” one sarcastic tweet implored recently.