Looking at the picture it should not be bad. If the durian flesh turns black or dark brown, it means it's moldy or rotten and can't be eaten.

Because I can't see the real thing, I'm going to provide a few more ways to recognize it:

Durian meat soft: This is a sign that the durian is beginning to deteriorate, if the durian meat becomes soft and flabby, no elasticity, it means that it has begun to ferment or rot, it is best not to eat it.

Durian meat odor: this is another sign of durian deterioration, if the durian meat has a sour smell or other abnormal smell, it means that it has been infested by bacteria or mold, and can not be eaten.

Durian shell discoloration: this is a sign that the durian has been stored for too long, if the durian shell turns gray or yellow, it means that it has lost its freshness, which may affect the taste and nutrition, and it is recommended to consume or discard it as soon as possible.