Some supernatural wonders are very much real, but originate from darkness. The Bible speaks of the woman who could foretell the future and made lots of money for people. She had a very real supernatural power of darkness working through her, until Paul cast it out of her and made everyone mad at him:
Acts 16:16-22 NASB
16It happened that as we were going to the place of prayer, a slave-girl having a spirit of divination met us, who was bringing her masters much profit by fortune-telling. 17Following after Paul and us, she kept crying out, saying, “These men are bond-servants of the Most High God, who are proclaiming to you the way of salvation.” 18She continued doing this for many days. But Paul was greatly annoyed, and turned and said to the spirit, “I command you in the name of Jesus Christ to come out of her!” And it came out at that very moment.
19But when her masters saw that their hope of profit was gone, they seized Paul and Silas and dragged them into the market place before the authorities, 20and when they had brought them to the chief magistrates, they said, “These men are throwing our city into confusion, being Jews,21and are proclaiming customs which it is not lawful for us to accept or to observe, being Romans.”
22The crowd rose up together against them, and the chief magistrates tore their robes off them and proceeded to order them to be beaten with rods.
Demonic signs and wonders can be very real. Don't adopt the thinking that it's just a matter of determining if the sign and wonder is real or not, and that all signs and wonders that are real are from God. Not true at all. Discernment has more to do with where the sign and wonder is coming from than if it's real or not. Especially in these last days:
2 Thessalonians 2:9-12
9that is, the one whose coming is in accord with the activity of Satan, with all power and signs and false wonders, 10and with all the deception of wickedness for those who perish, because they did not receive the love of the truth so as to be saved. 11For this reason God will send upon them a deluding influence so that they will believe what is false, 12in order that they all may be judged who did not believe the truth, but took pleasure in wickedness.