We know very little about the secrets of Medjugorje. First, Our has Lady allowed the third secret to be known, which is: There will a permanent, indestructable, supernatural sign left at the place of Our Lady's first apparition in Medjugorje on the hill Podbrdo at the conclusion of the apparitions.
Second, we know that an evil that faced the world, which was contained in the 7th secret was eliminated due to prayer and fasting. And lastly, we know that the 9th and 10th secrets are chastisements for the sins of the world. They can not be eliminated as the 7th secret but can be lessened by our prayers and fasting.