The attackers received access messenger using SMS codes sent when you log in from a new device.
Attackers can gain access to their Telegram account using SMS code
Several entrepreneurs reported that unknown had gained access to their correspondence in the Telegram. Thus, the problem faced by users with iOS and Android.
The attack on the smartphone began with the fact that the user came from a message service channel Telegram (official channel check verification) with a confirmation code that the user requested. After that, the user receives an SMS message with the same confirmation code and almost immediately the message that his account is logged in from a new device in Samara.
To hack into someone else’s account, the attackers themselves initiate a request to send a messenger SMS with the activation code, then intercept that TEXT and use the resulting code for the successful login in the messenger, says Group-IB. So they get access to all user data, including secret chats and photos that are stored in the messenger.
In order to access a TEXT, hackers can use special technical means or insides of the operators. In Group-IB has not yet figured out how the criminals, but in hacker forums on the darknet appeared the announcement of the sale of access to the messenger. For example, 100 thousand rubles offer to buy access to all correspondence of a person in WhatsApp, Telegram or Viber online for two to four days. And for 350 thousand rubles, you can access all remote from messenger of information. In this case, the attackers will use the help of “special forces”.