Sorry for this but from all indications given by you, it shows that the asset has been stolen or hacked and nothing can be done about it. The next thing that will be of great importance is knowing how it happened and applying caution else it might still happen again. As a suggestion, I suggest you cross-check the place you downloaded the wallet from. Also, check if in anyway you might have misplaced your private keys, backup phrases etc. And lastly your device might have been compromised via malware or virus, thus scan for better security.
