According to the Military Times the UAV, that Iran claims to have, did not suffer any kind of hostile activity:

Loren Thompson, an analyst at the Lexington Institute in Arlington, Va., said that the Iranians have no way to detect or engage the stealthy Sentinel.

“It would be almost impossible for Iran to shoot down an RQ-170 because it is stealthy; therefore, the Iranian air defenses can’t see it,” Thompson said. “Partly for the same reason, it is exceedingly unlikely that they used a cyber attack to bring down the aircraft.”