ANSSI: Why You Should Properly Restart Your Smartphone Regularly

Frequently restarting a smartphone can help shield it from sophisticated attacks. ANSSI recommends doing this correctly by switching the device off and back on, rather than using its restart function.

Restarting your smartphone properly to improve security

If you value your personal data, you should turn your smartphone off on a regular basis. For instance, the NSA advises restarting smartphones every week. Although this straightforward step does not provide 100% protection against sophisticated cyberattacks, it adds another layer of defence by making it harder for hackers targeting a smartphone.

Such advanced attacks generally depend on exploiting several vulnerabilities. When a device is switched off and then turned back on, the attacker may have to repeat the entire exploitation process. However, when restarting a smartphone for security reasons, it is better to do so properly: turn it off first, then switch it back on, instead of selecting the restart option.

This is, at any rate, what ANSSI says in a series of recommendations for the public. “Regularly switch your phone off and then back on instead of using the ‘restart’ function to counter certain spyware programs that can simulate a phone restart in order to mislead the user,” the agency states.

Updates and Wi-Fi: ANSSI recommendations

As well as advising users to restart their smartphones correctly, ANSSI says devices should be updated systematically and as soon as possible. These updates include operating-system fixes for vulnerabilities that hackers may exploit.

For Android devices, the agency also recommends turning off Wi-Fi, Bluetooth and NFC features whenever they are not being used. Location services should likewise be disabled when they are no longer needed. iOS users are advised by ANSSI to disable location services in Settings, to achieve a “true shutdown”, rather than turning them off through the Control Centre.

Managing applications to reduce the attack surface

Regarding apps, the agency recommends uninstalling or archiving those that are not used. While some people do this to free up storage space, ANSSI says removing them helps reduce the attack surface.