Indian Computer Emergency Response Team (CERT-In), under the Department of Information Technology, the apex body that monitors Internet security threats in the country, said a new worm 'Koobface' is propagating through social networking sites such as Facebook, MySpace, hi5, Bebo and Twitter.

CERT said the virus is spreading by sending spam containing a message with a link to a video to people on these sites.

The virus is particularly dangerous as it uses the infected machine to target other systems and distribute additional malware, generate 'pay per click' advertising revenue and steal sensitive data, CERT said on its website.

The Koobface works by taking control of social networking sites and spamming friends with messages containing links to sites that lead to malware traps.