My actual version of Worms is 3.6.28.0. Instead of a crack, it simply doesn't need a CD.
It's impossible to find the CD here where I live, because of its age. You had to go to mercadolivre, a site of anonymous trading, to find this. It'd be more or less the same thing of looking for GameBoyAdvance games.
Edit: There is only ONE person who sells this in the whole Brazil. Some people might even need to buy the product outside their contries. If you wanted to stop illegal downloads... that's very efficient.