The attack is interesting in that it requires a minimum of user interaction in order to spread. The attack looks to be part of a spam campaign that was designed to submit a certain comment over and over again. Many users have found themselves victimized by the attack, which, with its spam component, could damage users repuations on the service. The notorious Koobface worm has plagued Facebook since last year, with new versions popping up regularly throughout this summer. But as long as large numbers of potential victims gather in one place, the attackers will follow.
Source: https://threatpost.com/worm-attacks-reddit-092809/72268/