Thanks as always for your help.
I saw it from different PCs, and mobile devices, even different Internet connections, so I think is not on my side.
This is the brownser code of my store logo, showing the changed link to www.ly.com instead of my storehttps://drive.google.com/file/d/0B2nQNW7Afa5BeTVuRG5hZEpxU0U/view?usp=sharing
I asked the hosting to block the suspicious IPs, but they told me that it's not possible in a shared hosting, because maybe other users are not interested in blocking them ??
So I'm moving to another hosting, hoping to block that IPs...