IT contractors need to warn firms of the dangers of cyber attacks taking place via social networking sites, it has been claimed.

With more and more companies using social networking as part of media campaigns, it is becoming an intrinsic part of the way many firms work, according to security software vendor Kaspersky Lab.

Problems arise because employees using sites such as Facebook and Twitter will trust any links or files sent to them by their own contacts. Knowing this, cyber criminals are increasingly hacking these accounts to distribute malware, the firm claims.

David Emm, senior security researcher for Kaspersky Lab, said: "You get an approach that looks like it's from a legitimate contact and then you look at the item and you've got malware on your system.

"What we're seeing here is a social networking version of the standard phishing method."

Security researchers Network World recently published research which confirmed that cyber attacks using this method are on the rise.