I don't know if my question falls into this group or not.
Does anyone know if crysis wars is free to play online??

No, I think you get it when you buy Crysis Warhead or Crysis Maximum edition.

Hello,

Crysis Wars is the multiplayer part of Crysis Warhead, so it is not free.
You can get Crysis Wars by buying Crysis Warhead or the maximum edition.
I think you can also buy Crysis Wars only but I dont know if they changed that.

Crysinator

Crysis Wars is not free, it is however pretty cheap and comes with the Crysis Warhead singleplayer expansion.

If you are willing to wait a bit, you will most likely find some awesome deals on it, like the 75% off Steam deal that expired just a few days ago. EA also does deals very often ranging in the 30 - 50% area if you are a member of teh EA Gun Club, you can get some great promo codes.

i just want to know if crysis wars is free to play online also is it safe (no hackers, trojans etc).

your first question has been answered, when you have bought the game (crysis warhead) it is free to play online.
The second one, is it safe? It is as safe as any other game. When connected to the internet hackers can always try and attack you, but when playing Crysis Wars you don't have more risk then just being on the internet.

The only problem is that crysis wars isn't the best supported game of all time, and the community isn't very big to be honest. Still, worthwhile buying to play crysis anyway!