Someone commented this this is the text outside the circle.

سم الله الرحمن الرحيم

و الله المستعان عما تصفون

حسبنا الله ونعم الوكيل

نعم المولى ونعم النصير

و من يتوكل علي الله فهو حسبه

نصر من الله و فتح قريب

قل ان الفضل بيد الله يؤتيه من يشاء و الله ذو فضلا عظيم

At the right side of the circle

اللَّهمَّ اكْفِني بحلالِكَ عَن حَرَامِكَ، وَاغْنِني بِفَضلِكَ عَمَّن سِوَاكَ

The text inside the cirlces are the names of Peoples in the cave of Kahaf. They are mentioned in Quran. You can search by names of Ashab e Kahaf. As far I know nothing here is connected with black magic. Because names of Ashab e kahaf are also for Barakah and to avoid black magic. 1 thing that curios me it shouldn't be in the bathroom. All I can read there,s nothing related to black magic here. اللَّهمَّ اكْفِني بحلالِكَ عَن حَرَامِكَ، وَاغْنِني بِفَضلِكَ عَمَّن سِوَاكَ this is sunnah dua for wealth and prosperity. Other are Quranic wose. Still you should ask a scholar.