Buzz
1. Alert on the technique of call redirection for OTP theft
Stay vigilant against unfamiliar calls claiming to be network personnel
Perpetrators often impersonate customer service representatives from telecom companies, banks, or e-wallets, calling customers to guide them in using services, resolving any issues, and requesting customer confirmation actions on their mobile phones.
After the customer agrees to follow the instructions, they ask the customer to enter command codes on the keypad, such as **21*fraudster's phone number#OK (USSD protocol command). In reality, this is a call redirection feature that allows mobile subscribers to redirect calls to another phone number.
Upon successfully executing the Call Redirect command as instructed by the scammer, the customer's subscription remains active. They can still receive text messages (SMS) or connect to the network normally, but all incoming calls are redirected to the 'Fraudster's phone number' from that moment on.
After deceiving and gaining control over call reception, fraudsters log into victims' electronic wallet applications, social media accounts, etc., and declare a login password reset. They select the feature to receive notification calls for OTP codes, exploiting the previous redirection manipulation so that calls from the app's service center are redirected to the scammer's phone number. This makes it easy for them to hijack social media accounts, take control of funds in the wallet, and access bank accounts linked to the e-wallet.
Customers, take note when this icon appears unexpectedly
2. Advice from the network provider
To protect customers and minimize the damage caused by fraudsters, VinaPhone recommends the following:
- Be cautious of scam calls; do not execute the **21*Phone Number# command as instructed by these calls.
- If the phone shows unusual signs, such as not receiving incoming calls (with a call redirect icon next to the network logo), customers should immediately dial ##21# to cancel unintended call redirection and contact VinaPhone through the toll-free hotline 18001091 to check the status of their subscription, receive guidance, and get advice on how to handle the situation.
According to VinaPhone, besides the call redirection scam mentioned earlier, there are cases of fraud involving free 4G SIM replacements. VinaPhone specifies that they only offer SIM replacements to customers using outdated SIM cards (2G/3G SIMs).
To check the type of SIM card in use: send an SMS with the content 'DS4G' to the number 888 or dial the USSD code *0888#. For subscribers using 4G SIMs, VinaPhone does not make replacement calls.
Additionally, during SIM replacement, 'VinaPhone staff will contact and come directly to the customer's address, not remotely replacing SIM cards via phone or any online method,' the network representative stated.
The network also advises users to immediately contact them upon detecting unusual signs with the phone's SIM card, such as signal loss, inability to receive calls or messages, without clear reasons.
As reported by Tuổi trẻ
