According to a Barracuda survery, “One in 100 tweets today are malicious, and one in 60 Facebook posts are as well.” Their survery showed LinkedIn users, as of now, feel the safest, but that may not last for long. It appears LinkedIn attacks may cause more disruption and cause more of a stir, if compromised.
According to the research, Twitter mainly gets infected the same way search engine poisoning happens. Attackers try to cast grab the attention of as many viewers as possible and direct them right into getting infected. Facebook is less likely to have malicious code sneak into your system, but via your presumed trusted friends posting links on their wall, end-users often feel safer and more readily click on the links, allowing their systems to become infected.
More shocking, however, is Barracuda’s survey of sites on Google, Twitter, Bing, and yahoo over a 153 day period, and found an astounding 34,627 malware sites, with one in every thousand sites leading to malware.