One of these applications has recently been attacked by a big hack. As a result of this attack, information of 42 million users leaked to the Internet. It is not known whether each of these accounts belongs to a person or a person has more than one account. But if we think everyone has an account, it means that half of the Iranian population is exposed. Details of the Attack This practice, which is widely used in Iran, is thought to have been attacked before March 21st. Because by March 21, these 42 million user records had already leaked to the Internet. These data are thought to be leaked by an organization called the Av system (translation from Persian). According to Comparitech’s research, the data leaked to the Internet included: User account IDs Usernames Telephone numbers Secret keys This data, discovered on March 21, was removed from the Internet (or closed to access) in a few days, presumably on March 25. However, it must be said that 42 million user information is open to everyone during this passing period. So anyone who wants this data, any password etc. it was accessible without using it. Is there a connection with Telegram? Since Telegram is an open source application, which is widely used in our country, anyone can develop their own version. People often switch to alternative versions of Telegram as the Iranian Government tries to prevent Telegram use as much as possible. A Telegram spokesperson said in his statements about this development in Iran that this application is not directly connected with Telegram and added: “We can say that this data comes from one of the third party forks. Unfortunately, people in Iran continue to use the unofficial Telegram apps despite dozens of warnings. Since Telegram application is open source, it is necessary to take care of using the official application. ” Whether this attack is linked to the official Telegram application, the data leaked as a result of this attack belongs to real people. Although it is not possible to say exactly what personal information is leaking, these phone numbers on the Internet can be used for SIM attacks, various frauds.