Technology doesn’t stand still – this is true not only for legitimate businesses and users, but also for cybercriminals. Today, mass phishing mailings no longer have to be done through compromised servers. Classic methods have been replaced by a more advanced and dangerous method that allows fraudsters to literally surround their victims with a cloud of fraudulent messages, bypassing the defense systems of telecom operators. These are portable devices known as SMS blasters.
What is an SMS blaster and how does it work?
The SMS blaster is a compact device that simulates the operation of a real cellular base station (BS). It can be easily placed in a car, carried in a backpack, or set up in a high-traffic public place. Once activated, the device creates a fake signal that causes smartphones within a radius of up to a kilometer to automatically connect to it.
The key point of the attack is as follows: once a connection is established, the blaster forcibly switches the phone to the outdated and vulnerable 2G (GSM) communication protocol. This protocol does not support modern encryption standards, which gives attackers full control over the connection. By exploiting this vulnerability, the device is able to directly send phishing SMS to thousands of phones simultaneously, completely ignoring operator filters that would normally block such mass mailings.
From law enforcers to criminals: the dangerous transformation of technology
This technology is not entirely new. Originally, such devices, known as IMSI traps (Stingrays), were developed and used by law enforcement agencies for detection and data collection during investigations. However, in the hands of cybercriminals, it has become a powerful tool for mass fraud.
The efficiency of the method is astounding: the entire process – from creating a fake network to mass mailing – takes less than 10 seconds and remains virtually invisible to the average user. One such portable device can generate up to 100,000 fraudulent messages per hour. The problem has gone global: the first waves of attacks were recorded in Southeast Asia, after which the epidemic spread to Europe and South America.
How to protect yourself? Top tip
Although telecom operators have significantly strengthened their defenses and are fighting such attacks, it is still impossible to completely stop the flow of messages via SMS blasters. Therefore, users’ security is largely in their own hands.
The most effective way to protect yourself is to disable 2G protocol support in the settings of your smartphone. This will significantly reduce the risk of connecting to a fake base station.
- On Android: This function is usually available under Settings > Network & Internet > Mobile Network > Advanced Settings (or Android Advanced Protection). You need to select a mode that excludes 2G (e.g. “LTE/3G/2G (auto)” and select the no 2G option).
- On iPhone: To disable 2G, go to Settings > Cellular > Data Settings > Voice & Data. Here, you should select the “LTE” or “5G Auto” options. In some versions of iOS, this feature may be called “Lockdown Mode” in the advanced security settings.
It is important to note that even after disabling 2G, the phone can temporarily revert to this protocol in emergency cases to make an emergency call. However, for daily use, this protection is a solid barrier.
The goal of fraudsters remains unchanged – to gain access to confidential data: banking information, passwords and personal data via phishing links. Therefore, the golden rule of cybersecurity remains relevant: be vigilant, do not click on suspicious links from SMS and never give confirmation codes or passwords to unauthorized persons.
