T-Mobile's Latest Data Breach Linked to SIM Swap Attacks

Back in August, T-Mobile suffered a massive data breach impacting more than 50 million current, former, and prospective T-Mobile users, and now the cellular company is dealing with another smaller data breach incident.

tmobilelogo
Reports yesterday suggested that T-Mobile was aware of unauthorized activity affecting some customer accounts, and now, T-Mobile has confirmed that those reports were due to SIM swap attacks affecting a "very small number of customers."

In a statement to Bleeping Computer, T-Mobile said that impacted customers had been informed that they had been the victim of SIM swap attacks. In a SIM swap attack, social engineering is used to persuade T-Mobile employees to reassign the phone numbers linked to a person to someone else, allowing attackers to take over a phone number. This can be devastating, as phone numbers are often linked to email accounts, banking accounts, and other sensitive information.

We informed a very small number of customers that the SIM card assigned to a mobile number on their account may have been illegally reassigned or limited account information was viewed.

Unauthorized SIM swaps are unfortunately a common industry-wide occurrence, however this issue was quickly corrected by our team, using our in-place safeguards, and we proactively took additional protective measures on their behalf.

T-Mobile says that the attack has been mitigated and that the issue has now been corrected, but the company has not provided specific details on the number of customers impacted nor how the hackers were able to execute the SIM swap attacks.

In the August data breach, attackers were able to obtain phone numbers, addresses, birth dates, social security numbers, driver's license and ID info, IMEI numbers, and IMSI numbers for more than 50 million people, with the information offered up for sale.

T-Mobile CEO Mike Sievert apologized for the breach at the time, and said that T-Mobile was "truly sorry" for the incident, which was the result of a "bad actor" who used knowledge of T-Mobile's technical systems to gain access to testing environments, using brute force attacks to access T-Mobile's IT servers.

To prevent future attacks, T-Mobile entered into a long-term partnership with cybersecurity experts at Mandiant and with consulting firm KPMG LLP, and the company said that it was planning a multi-year investment to improve security.

Top Rated Comments

sw1tcher Avatar
28 months ago

No wonder Apple wants to transition into eSim
eSIM is not going to 100% prevent SIM swap attacks.

The weak link is the customer service rep approving the swap.
Score: 22 Votes (Like | Disagree)
VulchR Avatar
28 months ago
Time to start compensating people directly and substantially when their data are hacked.
Score: 20 Votes (Like | Disagree)
noone Avatar
28 months ago
I think its about time TMobile gets heavily fined for every data breach they have. I understand that, despite best efforts, things can happen. But TMobile gets hit over and over and over and over and over again. At this point its pure negligence.
Score: 14 Votes (Like | Disagree)
BigBlur Avatar
28 months ago
Just curious, how does eSIM solve this? It’s not like they are actually swapping physical SIM cards…
Score: 14 Votes (Like | Disagree)
Apple$ Avatar
28 months ago
Maybe it's time for Apple to start their own MVNO company. At least in the US.
Score: 13 Votes (Like | Disagree)
jz0309 Avatar
28 months ago
Guess their engagement with cyber security experts is not working yet…
Score: 12 Votes (Like | Disagree)

Popular Stories

Apple car wheel icon feature yellow

Apple Cancels Electric Car Project

Tuesday February 27, 2024 11:05 am PST by
Apple has canceled all plans to release an autonomous, electric vehicle, reports Bloomberg. Apple has been working on an Apple Car for more than a decade and invested millions of dollars into development before deciding it was not a viable project. Apple's Chief Operating Officer Jeff Williams today told approximately 2,000 employees working on the Apple Car that the project was canceled,...
iOS 18 Mock iPhone 16 Feature Gray

iOS 18 Rumored to Be Compatible With These iPhone Models

Tuesday February 27, 2024 6:31 am PST by
iOS 18 will be compatible with the iPhone XR, and thereby also the iPhone XS and iPhone XS Max models with the same A12 Bionic chip, according to a post on X today from a private account with a proven track record of sharing build numbers for upcoming iOS updates. The post was spotted by MacRumors contributor Aaron Perris, and it has since been deleted. However, this was likely because the...
Google maps feaure

Google Maps Finally Rolls Out Glanceable Directions

Wednesday February 28, 2024 2:07 am PST by
After more than a year since announcing the feature, Google Maps is finally rolling out glanceable directions on Android and iOS (via Android Police). The feature allows users to view turn-by-turn directions and a live ETA directly from their device's lock screen – information that was previously only visible when a phone was unlocked. Glanceable directions also work on the app's route...
iPad Air 5

iPadOS 18 Rumored to Drop Support for These iPad Models

Tuesday February 27, 2024 6:55 am PST by
iPadOS 18 will drop support for iPad models equipped with the A10X Fusion chip, according to a post on X today from a private account with a proven track record of sharing build numbers for upcoming iOS and iPadOS updates. This means that iPadOS 18 would not be compatible with the first-generation 10.5-inch iPad Pro or the second-generation 12.9-inch iPad Pro models released in 2017. It...
iOS 17

iOS 17.4 Coming Soon With These New Features for Your iPhone

Monday February 26, 2024 6:08 am PST by
In a press release last month, Apple confirmed that iOS 17.4 will be released in March, and the update includes several new features and changes for the iPhone. Key new features in iOS 17.4 include major App Store changes in the EU, Apple Podcasts transcripts, and an iMessage security upgrade. The update also adds new emoji and includes preparations for the launch of next-generation CarPlay...
M3 MacBook Air Feature

New MacBook Air Models Launching Next Month: 5 Features to Expect

Wednesday February 28, 2024 1:50 am PST by
The existing 15-inch MacBook Air arrived in June 2023, which is not that long ago in terms of Mac update cycles. However, Apple released the current 13-inch ‌MacBook Air back in June 2022. It is now the oldest Mac in Apple's current crop, having not been updated in 600 days. But rumors suggest that is unlikely to be the case for much longer. According to Bloomberg's Mark Gurman, Apple has...