Answer:
Prunes and all fruit, can spoil depending on a variety of conditions which include:
1. High levels of humidity contribute to the growth of molds and bacteria, even on dried fruits.
2. If the fruit wasn't thoroughly dried.
3. If the fruit wasn't treating with a preservative as part of the drying process.
If you live in a humid area and your fruit has not been treated with anything, it is recommended that you store the prunes in the refrigerator.