Shoutbox

WLM is secure in that sense...

It either does this like all other virusses and malware do their stuff:
It simply installs a program on your PC, which runs in the background, getting the pics from the webcam and sending it to the viewer upon request from the viewer.

As such, this doesn't work directly in Messenger. It is a 'standalone' program with a client part (the stuff which is installed on the viewer's pc) and a server part (the stuff which is installed on the victim's pc). The video stream is most likely not send over the Messenger network, but directly to the ip.

But, just as Messenger Plus! does, it would of course be possible to kind of integrate it into Messenger, at least for the viewer's part.

----

Or it patches the Messenger of the 'victim' in such a way that the victim wont see any video requests in Messenger and automatically agrees to such request... But this seems unlikely as it would involve a hell of a lot more work. And usually, malware like this is created by very lazy people...

----

Either way, it most likely always requires to install a piece of the software on the victim's computer.

So as long as you don't install any dodgy stuff (even if you get it from your 'friends') you're safe.