Hi Kevin, thank you very much 'cause i have done all of your steps, and i finally i deleted the folder Chameleon files in Documents, it disappeared, so I believe i successfully have removed this virus, following your advices. Anyway i still have the same problem of @ItsMrMToYou -> http://prntscr.com/kp1mr2
"Applicazione non trovata" means - "Application couldn't be found.".
I have already restored defaults characteristics for folders, but I still couldn't solve this problem.
Thank you anyway for solving me the problem with Chameleon!
Waiting for an answer :)