New SMS-based 2FA bypass circumvents Google's 2019 SMS restrictions

Spawn

Administrator
Verified
Staff member
Jan 8, 2011
21,152
ESET analysis uncovers a novel technique bypassing SMS-based two-factor authentication while circumventing Google’s recent SMS permissions restrictions
When Google restricted the use of SMS and Call Log permissions in Android apps in March 2019, one of the positive effects was that credential-stealing apps lost the option to abuse these permissions for bypassing SMS-based two-factor authentication (2FA) mechanisms.

We have now discovered malicious apps capable of accessing one-time passwords (OTPs) in SMS 2FA messages without using SMS permissions, circumventing Google’s recent restrictions. As a bonus, this technique also works to obtain OTPs from some email-based 2FA systems.
The apps impersonate the Turkish cryptocurrency exchange BtcTurk and phish for login credentials to the service. Instead of intercepting SMS messages to bypass 2FA protection on users’ accounts and transactions, these malicious apps take the OTP from notifications appearing on the compromised device’s display. Besides reading the 2FA notifications, the apps can also dismiss them to prevent victims from noticing fraudulent transactions happening.

The malware, all forms of which are detected by ESET products as Android/FakeApp.KP, is the first known to sidestep the new SMS permission restrictions.

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LASER_oneXM

Level 37
Verified
Feb 4, 2016
2,566
Researchers monitoring malware that affects Android devices discovered malicious apps that can steal one-time passwords (OTP) from the notification system. This development bypasses Google's ban on apps that access SMS and call logs without justification.

Google enforced the restriction earlier this year specifically to lower the risk of sensitive permissions where they are not necessary. In theory, this also translated into stronger protection for two-factor authentication (2FA) codes delivered via the short message service.

Cybercriminals found a way around this limitation and instead tap into the notifications to obtain the sensitive information. This method also opens up the door to getting short-lived access codes that are delivered via email.
 
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Local Host

Level 23
Verified
Sep 26, 2017
1,284
Both SMS and E-Mail based 2FA are useless and easy to exploit, any website not running 2FA with a proper Authenticator is poorly managed (and you should think twice before trusting them with any data).
 
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