If you want to protect your SIM card against attacks like these, there are some steps you can take.
Protect Against Socially Engineered Attacks
To protect against SIM card swaps, you should make it hard for hackers to find information about you. Hackers will use data they find about you online, such as names of friends and family or your address. This information will make it easier to convince a customer support agent that they are you.
Try to lock down this information by setting your Facebook profile to friends-only and limiting the public information you share on other sites. Also, remember to delete old accounts you no longer use to prevent them from being the target of a hack.
Another way to protect against SIM card swaps is to beware of phishing. Hackers may try to phish you to get more information they can use to copy your SIM. Be on the lookout for suspicious emails or login pages. Be careful where you enter your login details for any account you use.
Finally, consider what methods of two-factor authentication you use. Some two-factor authentication services will send an SMS message to your device with an authentication code. This means that if your SIM is compromised, hackers can access your accounts even if you have two-factor authentication on.
Instead, use another authentication method such as the Google Authentication app. This way the authentication is tied to your device, not your phone number, which makes it more secure against SIM card swaps.
To protect against SIM attacks you should also set up some protections on your SIM card. The most important security measure you can implement is to add a PIN code to your SIM card. This way, if anyone wants to make changes to your SIM card, they need the PIN code.
Before you set up a SIM card lock, you should ensure you know the PIN given to you by your network provider. To set it up, on an Android device go to Settings > Lock screen and security > Other security settings > Set up SIM card lock. Then you can enable the slider for Lock SIM card.
On an iPhone, go to Settings > Cellular > SIM PIN. On an iPad, go to Settings > Mobile Data > SIM PIN. Then enter your existing PIN to confirm, and the SIM lock will be activated.