Iranian hacker group knows who is on Telegram

Telegram encrypted messaging app leaked 15 million Iranian users’ phone numbers

Hackers obtained the mobile phone numbers of 15 million Iranian users of the Telegram encrypted messaging app, and hacked the accounts of more than a dozen of them, security researchers say.

The accounts were hacked through interception of SMS confirmation codes sent to the associated phone numbers, security researchers Claudio Guarnieri and Collin Anderson told Reuters.

The revelations show once again how use of encryption can pit technology companies against governments. Telegram founder Pavel Durov has in the past sided with Apple CEO Tim Cook against the FBI on the question of whether governments should have access to the contents of smartphones.

In this latest case it was a cyberespionage group said to have links with the Iranian government, Rocket Kitten, which identified 15 million Iranian users of Telegram.

The group did not leak the numbers, Anderson said. He and fellow security researcher Guarneri found the numbers on the Rocket Kitten servers, he said via Twitter.

The two plan to say more about these hacks, and many others directed at Iranians, in a presentation at the Black Hat security conference in Las Vegas on Thursday.

Telegram acknowledged the attacks on its service in a blog post, but played down their significance. "Certain people" had used its public APIs to check whether Iranian phone numbers were used for its service, and had ascertained this for 15 million accounts, the company said, but the content of the accounts could not be accessed through the API.

Information about which phone numbers are associated with accounts has to be public, otherwise users cannot find and message their friends through the service, the company said on its blog.

Checking phone numbers on such a large scale is no longer possible, though, as within the last year the company has placed limits on such use of its API, it said.

The company is aware that Telegram accounts can be hacked by intercepting SMS confirmation codes, but "this is hardly a new threat," it said. Last year it introduced an optional two-factor verification function combining SMS codes and passwords, and has been encouraging users in certain countries to turn this on if they think that their mobile carrier is intercepting their SMS codes.

"If you do that, there's nothing an attacker can do," the company said.

Anderson welcomed Telegram's API changes, but called for it to publish its security advice in the Farsi language to ensure more Iranian users were aware of the need to use two-factor verification.

If you are in Iran and use the mobile app, there are significant risks from government cooperation with telcos, he said via Twitter.

Join the newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Peter Sayer

IDG News Service
Show Comments

Cool Tech

Breitling Superocean Heritage Chronographe 44

Learn more >

SanDisk MicroSDXC™ for Nintendo® Switch™

Learn more >

Toys for Boys

Family Friendly

Panasonic 4K UHD Blu-Ray Player and Full HD Recorder with Netflix - UBT1GL-K

Learn more >

Stocking Stuffer

Razer DeathAdder Expert Ergonomic Gaming Mouse

Learn more >

Christmas Gift Guide

Click for more ›

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Walid Mikhael

Brother QL-820NWB Professional Label Printer

It’s easy to set up, it’s compact and quiet when printing and to top if off, the print quality is excellent. This is hands down the best printer I’ve used for printing labels.

Ben Ramsden

Sharp PN-40TC1 Huddle Board

Brainstorming, innovation, problem solving, and negotiation have all become much more productive and valuable if people can easily collaborate in real time with minimal friction.

Sarah Ieroianni

Brother QL-820NWB Professional Label Printer

The print quality also does not disappoint, it’s clear, bold, doesn’t smudge and the text is perfectly sized.

Ratchada Dunn

Sharp PN-40TC1 Huddle Board

The Huddle Board’s built in program; Sharp Touch Viewing software allows us to easily manipulate and edit our documents (jpegs and PDFs) all at the same time on the dashboard.

George Khoury

Sharp PN-40TC1 Huddle Board

The biggest perks for me would be that it comes with easy to use and comprehensive programs that make the collaboration process a whole lot more intuitive and organic

Featured Content

Product Launch Showcase

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?