Gtron Solutions, LLC

Twitter, Facebook, MySpace and other social networking sites may contain links that, when clicked, could trigger a security nightmare for unwitting users.

This was the stern warning issued by security companies on Monday as they raise the alarm over the rapid spread of security threats using these social networking sites.

Security experts from Symantec and Japanese firm Finjan said malicious links found in Twitter and similar sites have affected its user's PC.

“Spammers were using a Twitter-branded e-mail message in an attempt to convince the recipient to open up a .zip file to infect the victim's computer,” said Symantec in its security blog.

In a blog post about cybercrime, Gary Warner said that shortened URLs are particularly attractive to users but will eventually lead them to a chain of redirects that will compromise their system.

"When you only have 140 characters, using a shortened URL makes sense," he said. "The problem is that you just really don't know where those links are going — and because of that searching on Twitter is a security nightmare. As an example, searching on 'Transformers 2' tonight, the first link took me to a site telling me how I could get rich on the Internet,” said Warner.

Warner said they followed the malware links on Twitter and was led to phishing sites, eventually ending up asking you for payment for a fake anti-virus software.

Months before, Symantec was joined by other security firms on issuing calls for better security protection in social networking sites. On what is called 'security shortcomings' of social networking applications, researchers said Web woms and its variants can spread to hundreds of user accounts through the network of Twitter that produce up to 10,000 posts or “tweets” everyday.