Rahul Sasi, founder and CEO of CloudSEK, has revealed details of how attackers use the MMI code trick to hack users’ WhatsApp accounts.
According to Sasi, the attackers must first convince the victim to call a number that begins with a Man Machine Interface (MMI) code that the mobile phone provider has set up to enable call forwarding.
After the victim has been tricked into forwarding calls to their number, the attacker starts the WhatsApp registration process on their device. They choose the option to receive the OTP by voice call.
After receiving the OTP code, the attacker registers the victim’s WhatsApp account on their device and activates two-factor authentication. By activating 2FA, the attacker can prevent the rightful owner from regaining access.
The procedure is rigorous and has a high potential for success, as users are not familiar with the MMI codes or the mobile phone settings that disable call forwarding.
WhatsApp users are advised to activate 2FA on their account to guard against this type of attack. The two-factor authentication feature prevents malicious actors from gaining control of the account by requiring a PIN when a phone logs in to the messaging app.
The sources for this piece include an article in BleepingComputer.