A new variant of the Koobface worm spreading through Facebook leverages social engineering to bolster legitimacy, according to Trend Micro researchers. The variant looks like previous ones -- users are spammed messages claiming to come from a "friend" that contains a link to a video in which they supposedly appear. But the link leads to a site claiming a codec must be downloaded; click the download and the machine gets infected, enabling hackers to execute remote commands. — DK