How much content do you have in this ? if it is less, I would advice you to take downtime for one or two days and reinstall your wordpress with some other good theme. PM me if you need any help for wordpress and theme
Would you like me to resolve it for you as it will not occur again. I am a security expert and dealing with such stuff from a long time. When you fixed it last time - Is it a issue from .htaccess or some redirect plugin or ? .... This helps me to provide you better solution and also help me to stop it to happen again in future. Please feel free to contact..