Been seen before...
IIRC wasn't the Blaster or Nimda virus (as I remember them being called) followed up by a 'fix' virus that attempted to remove it.
Working for IT support at the time the cure was as bad as the virus...
I'd say that viral fixes (or even targeted as this is) is a great idea so long as a proper support mechanism is in place - as essentially who knows what's on that user's machine. And of course who wants to be responsible for supporting upwards of 25,000 disperate machines which are, by merit of being infected, utter pants.
Personally I'd keep quiet, watch what's going on and going where and try and start to find out a little more about who's running the whole thing. Then use something with terminal force...