If you have an Android phone, you can increase the security level of your device in just a few steps. Here’s how SMS attacks over 2G work and how to protect against them:
What are SMS Blasters?
SMS Blasters are tools that allow you to send bulk SMS messages to a large list of recipients simultaneously and automatically. Mass texting is not illegal in itself : it may be legitimate for promotional and informational purposes, but its use is regulated.
The problem is that some mass mailings are fraudulent and are carried out by fraudsters to steal information or payments from recipients. To bypass spam filters, scammers exploit vulnerabilities in the network. To do this, they use a small device that fits in a backpack, and which emits a signal similar to that of a cell tower to intercept mobile communications. The operation of the device is based on the imitation of a legitimate antenna, inserting itself as an intermediary between the targeted device and the operator’s network.
Unfortunately, these interception tools are not particularly complex, and they are easily available for purchase on the internet. According to Google, they are also easy to install and ready to go in no time. Scammers can even configure SMS fields to pose as an operator.
A simple but effective attack
On the user’s side, the interception technology presents the phone with what appears to be a nearby cell tower, tricking the device into switching from a legitimate network to a malicious one. Although newer, more expensive variants work over LTE, most readily available systems switch your phone to 2G – a much less secure network – before establishing a connection.
As Google explains, scammers create fake LTE or 5G network which performs a single function: downgrade the user’s connection to an obsolete 2G protocol. The same device also creates a fake 2G network, which attracts all nearby phones to connect to it. At this point, fraudsters abuse the well-known lack of mutual authentication in 2G and force connections to be unencrypted, allowing them to send bulk SMS attacks.
These attacks are primarily designed to distribute fraudulent links aimed at stealing credentials, but can also be used to spread malware.
News and press release from Google
Android 15 has just arrived, and the update already brings a number of new features that improve user security and privacy. One of these new features in Android 15 can warn users if their device is repeatedly asked for their IMSI phone ID (a unique number that allows a network to identify the user). It is this number that is used by interceptors. Updating to Android 15 can also restrict a device to only use encrypted connections, which should exclude most common interceptions that use unencrypted communications.
Going further, Google expanded its anti-interception campaign with a warning asking users to turn off 2G completely to protect against SMS Blaster attacks.
How to turn off 2G on Android
To turn off 2G, follow these steps on your Android phone:
- Go to settings
- Find and enter the “Networks and Internet” section
- Go to “SIM Cards”
- Then deactivate the “Allow 2G” option
Unfortunately, this option is not available on all devices. For example, we don’t find this option on some Samsung phones, including the S24 Ultra. Samsung may get up to speed in the coming weeks, as the option is available in some countries.
The iPhone is also likely to be exposed to SMS Blaster attacks, but it does not offer an option to disable 2G, except in “Isolation” mode: a feature which protects the user against cyber-attacks. attacks, but also greatly reduces the use of the telephone.
How to avoid being a victim of smishing (SMS phishing)?
The new features of Android and Google’s warning on the use of 2G make it possible to avoid a good number of cyber attacks. But if a suspicious SMS ever manages to slip into your inbox, be attentive and make sure you don’t fall victim to a scam. First of all, learn how to detect the main types of SMS scams:
Bank scams
Often, scammers try to pretend to be your bank in order to steal your banking credentials or ask you to confirm transactions. If in doubt, call your bank directly and do not communicate any sensitive data in response to the SMS.
Fake package tracking
Scammers can also fake a missed delivery notification and include a link to a fake site in order to charge the recipient for a supposed redelivery. The sites are even identical to that of Chronopost, which encourages many recipients to make a payment.
False fines
If you receive an SMS reporting a fine, do not pay it. This is certainly a phishing scam, since ANTAI, the organization responsible for processing offenses, never sends SMS.
Any subscription or public service is likely to be copied: from Netflix to Health Insurance, including mobile operators. If in doubt, you can consult the government platform www.cybermalveillance.gouv.fr specializing in fraudulent reports of this type.
🟣 To not miss any news on the WorldOfSoftware, , .
