The IRLeaks hackers claimed the attack, saying it stole the information of users of Tapsi, a cellphone taxi app popular with many people in Iran.
The hacking group has demanded 35 thousand dollars in ransom to not reveal the information of the Tapsi users.
The managing director of the cellphone taxi app company has confirmed the news.
Tapsi says its main mission is to facilitate urban trips and to make them safer and more cost-effective.