It's not good news I am afraid. It's blood basically and to show through the shell there is a significant amount.
This tort may have been dropped or received a blow, perhaps from another tortoise. Alternatively it could have blood poisoning called septicemia.
The prognosis is very poor indeed without immediate intervention from a vet and, even then, not good. As you have no access to a vet in Egypt, this is going to be one that you lose I'm afraid