Apple has built strong mobile security into iOS to protect against IMSI catchers, rogue cell towers, and mobile surveillance. However, iPhones are not immune to advanced attacks, so taking additional precautions is crucial.
I frequently receive calls from people concerned about their smart phone being monitored or tracked. It’s a complex issue, and sometimes distinguishing between real threats and unfounded worries can be challenging. To address mobile privacy these concerns, I’ve put together a brief guide on how to protect your phone from being snooped on.
It covers essential tips and in another post I will cover tools to enhance your Mobile Threat Defense, such as using Harmony Mobile and deploying robust firewalls like Check Point’s Spark 1500 series. Whether you’re at home or in the office, these measures can help safeguard your privacy. I hope you find this small blog helpful. Enjoy!
1. Protect Against IMSI Catchers & Rogue Towers
IMSI catchers (like Stingrays) trick your phone into connecting to a fake tower to intercept calls, SMS, and track location. To reduce the risk:
🔹 Use 4G/5G-Only Mode
IMSI catchers force downgrade phones to 2G/3G (which have weaker security).
💡 Limitation: Apple does not allow users to disable 2G completely (unlike Android), so iPhones are still at risk in areas with forced downgrades.
✅ How to enable 4G/5G-only mode on iPhone:
1. Go to Settings → Cellular → Cellular Data Options.
2. Tap Voice & Data.
3. Select LTE or 5G (Never use “Auto” if possible).
This prevents forced downgrades to 2G.
a) Disable Automatic Network Selection
- IMSI catchers pretend to be the strongest signal in an area.
- Manually selecting your carrier prevents automatic connections to rogue towers.
💡 Limitation: If you travel often, this must be manually reconfigured when switching networks.
✅ How to set manual carrier selection:
1. Go to Settings → Cellular → Network Selection.
2. Turn off “Automatic”. (not always available)
3. Select your legitimate carrier manually.
b) Use an eSIM Instead of a Physical SIM
- Some IMSI catchers can clone physical SIMs to impersonate your identity.
- eSIMs are harder to clone because they use remote authentication.
✅ How to switch to eSIM on iPhone:
1. Contact your carrier and request an eSIM activation.
2. Follow your carrier’s instructions to transfer your physical SIM to eSIM. (iPhones 14 and 15 uses it, USA only)
💡 Benefit: Even if an attacker clones your physical SIM, your eSIM remains protected.
2. Protect Calls & Messages from Interception
If an IMSI catcher intercepts your calls or SMS, using encryption is essential.
* Avoid Regular Calls & SMS (Use Encrypted Apps Instead)
* Regular calls and SMS are not encrypted and can be intercepted.
* Use end-to-end encrypted messaging apps like:
* Signal 📲 (best for privacy).
* iMessage & FaceTime (good, but Apple controls encryption keys).
* WhatsApp (end-to-end encryption enabled by default).
✅ How to use encrypted messaging:
* For calls, use FaceTime Audio or Signal Voice Call instead of regular calls.
* Â For texting, use Signal or iMessage (but disable SMS fallback).
💡 Limitation: If the other person uses regular SMS/calls, you cannot control their security.
3. Protect Internet Traffic from Stingrays
Some IMSI catchers act as fake cell towers AND fake internet providers, intercepting your web traffic.
🔹 Use a VPN to Encrypt Your Data
A VPN (Virtual Private Network) prevents eavesdroppers from seeing your web activity.
💡 Benefit: Even if your phone connects to a rogue tower, your internet data remains encrypted.
✅ How to set up a VPN on iPhone:
1. Use a trusted VPN provider like ProtonVPN, Mullvad, or NordVPN.
2. Install their iOS app and enable VPN at all times.
3. Go to Settings → VPN & Device Management → Turn on VPN Always-On Mode (if supported).
4. Prevent Tracking & Location Leaks
IMSI catchers can track your real-time location by forcing your phone to reveal its IMSI (International Mobile Subscriber Identity). Here’s how to reduce tracking:
🔹 Turn Off Cellular When Not in Use
- If you’re in a high-risk area, put your phone in Airplane Mode (with Wi-Fi & Bluetooth off).
- This prevents forced connections to rogue towers.
How to do this quickly:
- Open Control Center (swipe down from the top right).
- Tap Airplane Mode.
- Make sure Wi-Fi and Bluetooth are off too.
💡 Limitation: You won’t receive calls/SMS while in Airplane Mode.
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✅  Use a Faraday Bag for High-Risk Situations
- If you’re targeted by surveillance, use a Faraday bag to block all wireless signals.
- This completely isolates your iPhone from rogue towers.
💡 Best for journalists, activists, and high-risk individuals.
5. Detecting IMSI Catchers (Advanced Users)
Since iPhones do not allow IMSI catcher detection apps (like Android’s SnoopSnitch), alternative methods are needed:
💡 Best for professionals needing real-time network security.
🔹 Use a Portable IMSI Catcher Detector
- Devices like Crocodile Hunter, Cell-Site Simulator Detectors, or CryptoPhones can detect fake towers.
- These tools monitor cell tower anomalies, such as:
- Frequent network switches.
- Unknown base stations.
6. Protect Against Spyware & Zero-Click Exploits
🔹 Keep iOS Updated
- NSO Pegasus spyware has exploited iMessage and FaceTime vulnerabilities in the past.
- Apple regularly patches these exploits, so keeping iOS up to date is crucial.
✅ How to enable automatic updates:
1. Go to Settings → General → Software Update.
2. Turn on Automatic Updates.
💡 When enabled: iMessage, FaceTime, and web browsing become highly restricted, preventing zero-click exploits.
Use Lockdown Mode (High-Risk Users)
Apple introduced Lockdown Mode in iOS to protect against nation-state spyware.
✅ How to enable Lockdown Mode:
1. Go toSettings→ Privacy & Security.
2. Scroll down toLockdown Mode→ Enable it.
💡 When enabled: iMessage, FaceTime, and web browsing become highly restricted, preventing zero-click exploits.
Final Summary: Best easy to do Mobile Security tips:
|
Security Feature |
Recommended Setting |
|
4G/5G Only Mode |
✅ LTE or 5G (Disable 2G/3G if possible) |
|
Manual Carrier Selection |
✅ Turn off “Automatic” & select your carrier |
|
Use eSIM |
✅ Avoid physical SIM when possible |
|
Encrypted Calls & Messages |
✅ Use Signal, iMessage, or WhatsApp |
|
VPN for Secure Internet |
✅ Enable VPN at all times |
|
Turn Off Cellular When Needed |
✅ Use Airplane Mode in high-risk areas |
|
Faraday Bag for Maximum Privacy |
✅ Use in extreme surveillance situations |
|
Software Updates |
✅ Keep iOS up to date |
|
Lockdown Mode |
✅ Enable for high-risk individuals |
Conclusion:
Apple has strong security protections, but IMSI catchers, spyware, and rogue cell towers can still track or intercept communications under certain conditions. By making the right settings changes, using encryption, and taking extra precautions, you can significantly reduce your exposure to surveillance threats.
But if you still have concerns, the truth is that the best protection is to not use technology—yet, you can still be heard.Â