YoVille will NEVER ask for your password, so please be wary of malicious emails and/or forum posts that request your password, including via web links.
Turn your two step on and change your password. I haven't had an issue ever with that on this forum, I've been playing since 2009. You can review what devices are logged into your account through your facebook settings. How two-factor authentication works on Facebook: https://www.facebook.com/help/148233965247823