Less than a third (29 percent) of firms have warned their staff about the risk associated with social networks, says Netgear.

Research by the networking equipment manufacturer revealed nearly half (47 percent) of all organisations surveyed use social networks to interact with customers while 59 percent said their staff use Facebook, Twitter and other social media sites to converse with colleagues. However, only 42 percent actively encourage employees to regularly update their security settings, and more than half (52 percent) admit to not having updated their security settings in the past six months

Furthermore, only 34 percent of businesses have installed a content filtering system to ensure their PCs are not infected by malware.

"We all love social media tools as they help us to discover and share content at the click of a button. The problem is that just as you can rapidly pass on information, so can you rapidly pass on a threat," said Jason Leung from Netgear.

"In fact, social media is the biggest security challenge posed to SMBs, since it can conspire to point you towards websites that might be infected. Your friend or colleague shares a link with you, so you make an assumption that it's safe since it's come from somebody you trust. But this simply isn't the case. SMBs need to think about how they can encourage diligence among their employees, since businesses are still getting stung by the kind of threats which have become common place."