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
12 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
12 months ago
Time to start compensating people directly and substantially when their data are hacked.
Score: 20 Votes (Like | Disagree)
noone Avatar
12 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
12 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
12 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
12 months ago
Guess their engagement with cyber security experts is not working yet…
Score: 12 Votes (Like | Disagree)

Related Stories

tmobilelogo

T-Mobile CEO Apologizes for Data Breach, Shares Info on Future Security Plans

Friday August 27, 2021 1:03 pm PDT by
T-Mobile CEO Mike Sievert today penned a letter to T-Mobile customers apologizing for the recent data breach that impacted more than 50 million current, former, and prospective T-Mobile users. Data that included names, phone numbers, addresses, birth dates, social security numbers, driver's license and ID info, IMEI numbers, and IMSI numbers was stolen and has been offered for sale. "We...
apple bitcoin hack

22-Year-Old UK Citizen Arrested for 2020 Twitter Hack Affecting Apple

Wednesday July 21, 2021 10:47 am PDT by
The United States Justice Department has continued pursuing those responsible for a 2020 Twitter hack that saw the accounts of high-profile companies and individuals hacked as part of a Bitcoin scam. Several people have already been arrested and charged for the attack, and the DoJ today announced (via The Verge) that 22-year-old Joseph O'Connor, aka "PlugWalkJoe," has also been arrested....
iPhone SE 3 stacked

Apple Using Streamlined Purchase Process for T-Mobile and AT&T iPhone SE Buyers

Thursday March 17, 2022 2:50 pm PDT by
Apple is streamlining its iPhone purchase process with the launch of the iPhone SE, and has introduced a new buying method that allows customers to purchase T-Mobile and AT&T devices without inputting their current carrier information. As outlined by Bloomberg, customers typically need to provide their wireless phone number and social security number when making an iPhone purchase, a process ...
tmobilelogo

T-Mobile Data Breach Included Personal Information of Almost 50 Million Customers

Wednesday August 18, 2021 5:41 am PDT by
T-Mobile has issued a statement with further details about a cyberattack that the company confirmed earlier this week, confirming that the data breach included the personal information of almost 50 million current, former, and prospective customers. Late last week, T-Mobile confirmed that a forum post that purported to offer data from more than 100 million people was the result of a company...
oculus health app

Oculus Quest 2 Movement Data Will Sync With Apple Health App Starting in April

Thursday March 10, 2022 11:07 am PST by
Facebook parent company Meta today announced an upcoming fitness update for the Oculus Quest 2, which will allow fitness data captured during VR workouts to be integrated with the Apple Health app. Right now, when people exercise with interactive games like Liteboxer, Beat Saber, or Dance Central using the Oculus Quest 2, the data can only be viewed on the Oculus Mobile app on the headset...
tmobilelogo

T-Mobile Says an Additional 5.3 Million Customer Accounts Were Compromised in Data Breach

Friday August 20, 2021 9:21 am PDT by
T-Mobile earlier this week shared details on a data breach where hackers gained access to the personal information of close to 50 million current, former, and prospective customers. At the time, T-Mobile said that data from 7.8 million current customers had been compromised, as well as information from 40 million former or potential customers. In an updated statement provided today, T-Mobile ...
iphone se black

T-Mobile Will Pay Off Your Current Phone Up to $1,000 If You Switch

Thursday October 21, 2021 8:47 am PDT by
T-Mobile today announced that, starting October 22, it will pay off a qualifying customer's remaining eligible smartphone payments up to $1,000 via virtual prepaid MasterCard when they switch to the carrier in the United States. The limited time offer is designed to allow customers to switch from their current carrier to T-Mobile and continue using their existing smartphone without cost....
iCloud General Feature

UK Network Operators Target iCloud Private Relay in Complaint to Regulator

Sunday March 13, 2022 3:48 am PDT by
A group of UK network operators have formally urged the UK's Competition and Markets Authority (CMA) to regulate iCloud Private Relay, claiming that Apple's privacy service is anti-competitive, potentially bad for users, and a threat to national security. In its response to the CMA's Interim Report on mobile ecosystems, Mobile UK, a trade association of British mobile network operators,...

Popular Stories

maxresdefault

Can't Get an iPhone 14 Pro? Here's Why You Should Wait for the iPhone 15 Ultra

Monday December 5, 2022 11:44 am PST by
Due to production issues at Apple supplier factories in China, the iPhone 14 Pro and iPhone 14 Pro Max are backordered and basically out of stock at every store. If you were planning to gift or receive an iPhone 14 Pro model for the holidays and didn't already get one, you're basically out of luck because they're gone until late December. Subscribe to the MacRumors YouTube channel for more ...
Apple advanced security Advanced Data Protection screen Feature

FBI Calls End-to-End Encryption 'Deeply Concerning' as Privacy Groups Hail Apple's Advanced Data Protection as a Victory for Users

Thursday December 8, 2022 2:45 am PST by
Apple yesterday announced that end-to-end encryption is coming to even more sensitive types of iCloud data, including device backups, messages, photos, and more, meeting the longstanding demand of both users and privacy groups who have rallied for the company to take the significant step forward in user privacy. iCloud end-to-end encryption, or what Apple calls "Advanced Data Protection,"...
General iOS 16 Feature Yellow

iOS 16.2 for iPhone Launching This Month With These 8 New Features

Thursday December 1, 2022 8:44 am PST by
Apple plans to publicly release iOS 16.2 for the iPhone in mid-December, according to Bloomberg's Mark Gurman. The update remains in beta testing for now, with at least eight new features and changes already uncovered so far. iOS 16.2 introduces a number of new features, including Apple's new whiteboard app Freeform, two new Lock Screen widgets for Sleep and Medications, the ability to hide...
maxresdefault

Hands-On With Apple Music Sing in iOS 16.2

Wednesday December 7, 2022 12:24 pm PST by
With the iOS 16.2 release candidate that came out today, Apple added the new Apple Music Sing feature that was announced earlier this week. We thought we'd check out the new karaoke feature to see how it works. Subscribe to the MacRumors YouTube channel for more videos. Apple Music Sing is available on modern iPhones and iPads, as well as the newest Apple TV 4K. It's built in to the Apple...
Apple car wheel icon feature yellow

Apple to Charge Under $100,000 for Apple Car, Launch Planned for 2026

Tuesday December 6, 2022 2:31 pm PST by
Apple is aiming to launch an Apple-branded consumer-oriented vehicle by 2026, and its goal is to hit a price point under $100,000 to make the car appeal to a wider range of customers, reports Bloomberg. Apple initially planned to design a car that might look similar to Canoo's Lifestyle Vehicle, where passengers could face one another in a limousine-style car with no steering wheel or...
General iOS 16 Feature Yellow

iOS 16.2 for iPhone Expected to Launch Next Week With These 12 New Features

Thursday December 8, 2022 7:05 am PST by
iOS 16.2 is expected to be released next week following nearly two months of beta testing. With last-minute additions like Apple Music Sing and Advanced Data Protection, the software update now has over a dozen new features for the iPhone. Below, we've recapped many of the new features coming with iOS 16.2, including Apple's new whiteboard app Freeform, two new Lock Screen widgets, the...
introducing apple music sing

Apple Music Adding a Karaoke Experience With Apple Music Sing

Tuesday December 6, 2022 7:09 am PST by
Apple today announced Apple Music Sing, a new feature in Apple Music that lets users sing their favorite songs with adjustable vocals and more. Apple Music Sing will utilize Apple Music's real-time lyrics to allow users to sing to their favorite songs using adjustable vocals, background vocals, and duet view to allow more than one singer.Apple Music Sing includes: Adjustable vocals: Users...
Twitter Feature

Twitter to Charge $11 Per Month for Twitter Blue on iPhone, $7 on Website

Wednesday December 7, 2022 6:47 pm PST by
Twitter plans to charge $11 per month for a Twitter Blue subscription on the iPhone in order to account for the 30 percent cut that Apple takes from in-app purchases, reports The Information. On the web, Twitter Blue will be priced at $7 per month. Prior to when Twitter Blue was paused, Twitter was charging $7.99 for a subscription, but the pricing will change before it relaunches. According ...
Apple advanced security Advanced Data Protection screen Feature

Apple Announces End-to-End Encryption Option for iCloud Photos, Notes, Backups, and More

Wednesday December 7, 2022 10:00 am PST by
Apple today announced it is expanding end-to-end encryption to many additional iCloud data categories on an opt-in basis for enhanced security. iCloud already protects 14 data categories using end-to-end encryption by default, including the Messages app when backups are disabled, passwords stored in iCloud Keychain, Health data, Apple Maps search history, Apple Card transactions, and more,...