A issue of Rakuten Mobile phones being hijacked

Rakuten Mobile has been alerting users to an incident of unauthorized use of eSIMs since April 23, 2024.

A third party was found to be illegally using mobile communication services by obtaining users’ Rakuten IDs and passwords through an unauthorized website and reissuing SIM cards that needed to be replaced as eSIMs.

We have just reported on SIM swap on this site, and we must continue to be careful about such cases.

How to prevent SIM swap

Europol (European Criminal Police Organization) recommends the following


  • Keep device software up-to-date. Do not click on links or download attachments in suspicious e-mails (to prevent malware and phishing from leaking personal and other information)
  • Do not reply to suspicious e-mails or communicate by phone with senders requesting personal information
  • Do not carelessly disclose personal information online.
  • Use authentication apps or token devices for one-time passwords rather than SMS for two-factor authentication
  • If possible, do not tie your phone number to sensitive accounts.
    (Use a landline phone number, not a cell phone, as the phone number registered with the bank may be used for identification purposes)
  • Set a PIN on the SIM (to prevent misuse if the SIM is stolen).
  • In addition to this, it is also important to do the following
  • Set up your cell phone company to receive notifications via email when you log in to their services.
    (It will make it easier to notice that your MNP is being cancelled without your permission)
  • Check to see if the SIM has been deactivated.

A SIM with the same number cannot exist, and if it is reissued, your existing SIM will become invalid and communication will be disabled. If this situation occurs, you should immediately contact your cell phone company and ask them to deactivate the SIM once it is in place.

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