That hackers are using sites such as Facebook, LinkedIn and MySpace to launch attacks is no revelation. New statistics, however, show just how effective malware on social networking sites can be.
In its "Malware Evolution 2008" report, published in February 2009, Kaspersky Lab revealed that malicious code distributed via social networking sites has a success rate of 10 percent in terms of infections, making it 10 times more potent than malware distributed via e-mail.
"In 2008 we increased the collection of malicious files relating to social networks by approximately 26,000," said Stefan Tanase, a security researcher for the Kaspersky Lab Global Research and Analysis Team. "In 2008 alone we processed more of those samples than in the total of all years prior to 2008, making the growth rate exponential. Our collection of malicious software samples reached 43,000 at the end of last year."
Tanase said he expects that number to hit 100,000 by the end of 2009. According to McAfee, 800 new variants of the notorious Koobface virus were discovered in March alone. Social networking sites have also been hit by malware hidden in seemingly legitimate third-party applications.
No particular site is more dangerous than others, Tanase said. Different sites are popular in different regions of the world, and attackers follow the users.
"It's very hard for social networking sites to do better," he said. "Their business is about having an easy-to-use Website, so that everyone can join. The problem is that usability and security don't really go hand in hand most of the time."
For enterprises, that means developing policies to control the use of social networks by employees. Organizations can instruct employees not to mention the company name on social networking sites, for example, and can couple that with education on configuring privacy settings and general Web safety.
"Blocking access to social networking site[s] is not going to work in the long run," said Chenxi Wang, an analyst with Forrester Research. "As younger employees join the work force, they increasingly expect to have access to social networking sites from work, [so] having such a restrictive policy will damage the company's [prospects of attracting] employees and ultimately may become a competitive advantage [to competitors]."
As for basic security advice, Tanase advised users to limit the code executed inside their browsers to trusted sources only and to make sure the operating system, anti-virus application and other software are fully patched and up-to-date.
"When talking about social networks, even though they are made of users wandering throughout cyber-space, we should not forget we're actually talking about real people, actual human beings that have friends and relationships," he said. "These relationships are usually based on trust, so the bad guys are trying to exploit this trust."