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Traffic Interception and Remote Mobile Phone Cloning with a Compromised Femtocell and What You Can Do to Protect Yourself

As our reliance on mobile devices increases, so do the risks associated with their use. One such risk is the compromise of mobile network infrastructure, which can enable attackers to intercept phone calls and text messages, clone mobile phones, and gain access to cellular provider network resources. In this article, we will discuss how attackers can exploit vulnerabilities in femtocells and what end-users can do to protect themselves.

What is a Femtocell?

A femtocell is a small, low-power cellular base station that is typically used to provide cellular coverage in areas with poor network coverage or where additional capacity is needed. Femtocells connect to the cellular provider’s network via the Internet and use a broadband connection to route calls and data to and from the mobile device.

How Can Attackers Exploit Femtocells?

Attackers can exploit vulnerabilities in femtocells to intercept phone calls and text messages, clone mobile phones, and gain access to cellular provider network resources. In a 2013 Defcon presentation titled “Traffic Interception and Remote Mobile Phone Cloning with a Compromised CDMA Femtocell”, researchers demonstrated how attackers could use a compromised femtocell to intercept phone calls and text messages and even clone mobile phones remotely.

The researchers showed how an attacker could exploit vulnerabilities in the femtocell’s software or firmware, allowing them to gain access to the cellular provider network resources and perform malicious activities such as making phone calls or sending text messages at the victim’s expense. The attacker could also clone the victim’s mobile phone, effectively creating a “twin” of the victim’s phone that could be used to make calls, send texts, and access data on the cellular provider’s network.

How Can You Protect Yourself?

There are several steps that end-users can take to protect themselves against femtocell attacks:

  1. Update your mobile device regularly: Ensure that your mobile device is running the latest software updates, as these often include security patches that address vulnerabilities that could be exploited by attackers.

  2. Use a VPN: Consider using a VPN to encrypt your traffic and protect your data when using public Wi-Fi or other unsecured networks. You should consider your cellular traffic insecure and untrusted just like public Wi-Fi.

  3. Monitor your mobile device activity: Regularly check your mobile device’s activity and review your billing statements to identify any suspicious activity.

  4. Contact your cellular provider: If you suspect that your mobile device or network has been compromised, contact your cellular provider immediately to report the issue and seek assistance. We have some additional guidance on what to do if you suspect you’re compromised here .

  5. Use Secure Messengers and Voice Applications: If possible, you should be using applications like Signal, Wickr, or Wire. We discuss this more in detail here .

Conclusion

Femtocell attacks can have serious consequences, including the interception of phone calls and text messages, mobile phone cloning, and unauthorized access to cellular provider network resources. By taking steps to secure your mobile device, using a VPN, being cautious of unknown networks, and monitoring your mobile device activity, you can protect yourself against these types of attacks. Remember to contact your cellular provider if you suspect that your device or network has been compromised.