Would you notice if someone were stealing your phone number? Here’s what it could look like:
Pretty innocuous, right? Weird, but would you immediately go into lockdown and damage control mode? You should, because that first message (the bottom one) means someone is taking over your phone number. It means someone has fooled your carrier (Verizon, in this example) into changing the password for your account to one they know. Once they have the password and you don’t, your phone number is their phone number. And someone who controls your phone number is minutes away from taking over all your critical online accounts.
Next, the new owner of your phone number will port the number to another phone or carrier. Then they can impersonate you and wreak havoc on your finances and online accounts. They can even use sign in using two-factor authentication if you use text-messaging to authenticate your logins. (It’s better to use an app like Google Authenticator or Authy.)
The above text message actually came to an employee for Coinbase, a wallet service for digital currencies Bitcoin and Ethereum. Coinbase published an account of the attempted takeover, along with the steps it took to lock down its systems and recover the phone number.