It seems a hacker is using my phone number to make fraudulent account, and I would like to prevent that.

Usually, if a person has your phone number, they're not able to make an account because a verification code is sent which a hacker wouldn't be able to see. Strangely, I have found that several services have my phone number already enrolled (chat GPT, OfferUP, and paypal).

It appears that a hacker is able to receive texts sent to my phone number, as that's the only explanation for how they can making accounts using my phone number in those services indicated. (reading online, it appears that maybe they copied my IMSI and Authentication key)

I've recently just requested a new SIM card, since based on my reading a hacked SIM card would cease to exist when a new one is activated, but it I received a notification from Paypal indicating my number was connected to an account, so it seems the issue is coming up again.

Are there any suggestions to prevent this problem? I'm unable to make an offerUp and ChatGPT account because my phone number was already used and/or its restricted. I'd like to prevent further similar occurrences.

Thank you in advance

  • 3
    reset your phone to factory defaults? Your phone might be compromised.
    – schroeder
    Commented Oct 28, 2023 at 19:34
  • I'll probably be doing this as well. This would have to be caused from my downloading a malicious file doesn't it? Seems strange seems i'm wary of that sort of thing, but if that's the only explanation, then I must have failed somewhere Commented Oct 30, 2023 at 21:16
  • Your phone can get compromised in a few ways.
    – schroeder
    Commented Oct 30, 2023 at 21:46

1 Answer 1


You need to figure out if the issue is with your phone or with the infrastructure - mostly your Mobile Network Operator. SS7 backend networks are known to allow different spoofing scenarios which came from the dated standard itself but for which MNOs are working on countermeasures like signaling network firewalls. Also the MNO itself might have weak procedures to get duplicate of SIM card. The last one and the first you should check is the phone itself.The exact model of phone and versions of firmware would be needed to answer this question more preciesely.Also it would help if you point the MNO and if you are in your home country or roaming. Have in mind if the number was already compromised some service provider often rely on the fact you have phone number base service enrolled on other service - e.g online banking #1 will let you open account if online banking #2 using the same verification methods already opened one for you and you can authorize banking #1 account open using banking #2 API.

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