T-Mobile Hack Spiderwebs, Affecting Google Fi and Its Customers

You may remember one of our recent posts about T-Mobile's eighth hack in the last five years, as most cybersecurity news outlets were all over the story. Previous to this, we were unaware of the full effects of the breach, as quite a few individuals and businesses use the cell provider. Unfortunately, we've found that one of these businesses appears to be Google Fi, Google's cell network provider. 

How Did the Breach Occur?

The breach occurred after the T-Mobile hack that started in November 2022. The breach affected Google because Google Fi is an MVNO (an acronym for Mobile Virtual Network Operative) that piggybacks off Sprint and T-Mobile. "In a perfect world, the MVNO uses enough network to create a contribution to the organization without being detrimental," said Doug Chartier of T-Mobile in a 2013 statement. "That's the holy grail."

What Information Was Viewed or Stolen?

The details the hacker accessed were less sensitive than other breaches we've reported on, though the details can still have incredibly detrimental effects. TechCrunch was able to access the email sent to customers, which explained that SIM card serial numbers, phone numbers, mobile service plan details, and account status were all affected by the breach. One Redditor, whose username is "regexer," explained that their email contained a notice that the hacker had SIM swapped their device. SIM swapping is a hacking method where a SIM card serial number is input into a device that the SIM card is not in and accessing other accounts in the hacked device. These methods can easily mess with people's lives, giving the hacker access to things like financial apps and accounts and personal messages and pictures.

How Did Google Fi Admit to the Breach?

Google Fi admitted to the breach by sending the emails mentioned above to the victims. These appear to have changed based on the victim, so we don't know the full extent of the breach. The affected Redditor, "regexer," said, "under the heading "What does this mean for me?", my email includes the following bullet: Additionally, on January 1, 2023, for about 1 hour 48 minutes, your mobile phone service was transferred from your SIM card to another SIM card. During the time of this temporary transfer, the unauthorized access could have involved the use of your phone number to send and receive phone calls and text messages."

What Will Become of the Stolen Information?

The stolen information will likely be used in credential-stuffing attacks and may also be sold. There is a surprisingly large number of things the hacker can do with the stolen information, but, luckily, you also have quite a few options to combat it.

What Should Affected Parties Do in the Aftermath of the Breach?

After this breach, you should file a police report. This step is often overlooked, but it can be greatly beneficial in the event of identity theft or the like. You should also invest in identity and credit monitoring, which is very useful and will alert you to the unauthorized use of your credentials and tell you if your information is ever found on the dark web.