Iranian hack group "Rocket Kitten" have hacked over 15million users account on the highly secured Telegram instant messaging service, the biggest known breach to be reported on the encrypted communication system, researcher said.
According to cyber researcher Collin Anderson and Amnesty International technologist Claudio Guarnieri, who have been studying Iranian hacking groups for three years. said that the vulnerability lies in the use of sms to activate new user account on Telegram. They said when a verification sms is sent to the user, the code can be easily intercepted by the the phone company and then shared with a hacker who in turn would add new devices to the person Telegram account, enabling them to read all chats and histories recorded on the app.
"We have over a dozen cases in which Telegram accounts have been compromised, through ways that sound like basically coordination with the cellphone company," Anderson said during an interview.
A spokesman for Telegram said customers can defend against such attacks by not just relying on SMS verification. Telegram allows - though it does not require - customers to create passwords, which can be reset with so-called "recovery" emails.
"If you have a strong Telegram password and your recovery email is secure, there's nothing an attacker can do," said Markus Ra, the spokesman.
The victims most targeted in the hack are opposition organizations and political activist involved in reformist movements, though the researchers declined to name citing concerns on safety.
Telegram is widely known for its end to end encryption and it boost of over 100 million active users all over the in south America, Asia and even more popular in the middle east. Iran estimated to have over 20 million users.
Last year November, the U.S. - Isreali security firm Check Point said the Iranian hack group "Rocket Kitten major targets are mostly the Israeli nuclear scientists, members of the Saudi royal family, NATO officials and Iranian dissidents