T-Mobile has announced a data breach caused by an email vendor being hacked that exposed the personal and financial information for some of its customers.

In 'Notices of Data Breach' posted to their web site, T-Mobile states that their email vendor was hacked and an unauthorized person was able to gain access to T-Mobile employee's email accounts.

Some of the email accounts that were hacked contained T-Mobile customer information such as social security numbers, financial information, government ID numbers, billing information, and rate plans.

To alert customers of the data breach, yesterday T-Mobile began texting customers affected by the data breach. These texts state that T-Mobile "recently identified and shut down a security event involving some of your account information" and contain a link to a page containing more information.

T-Mobile Data Breach Notification Text

Source: Reddit

These text messages contain a link to one of the two "Notice of Data Breach" pages on T-Mobile's site depending on what data was exposed.

For users who had their financial information exposed, they will be directed to https://www.t-mobile.com/responsibility/consumer-info/pii-notice.

"The personal information accessed could include names and addresses, Social Security numbers, financial account information, and government identification numbers, as well as phone numbers, billing and account information, and rate plans and features."

For those who did not have their financial information impacted, they will be directed to https://www.t-mobile.com/responsibility/consumer-info/cpni-notice.

"The information accessed may have included customer names and addresses, phone numbers, account numbers, rate plans and features, and billing information. Your financial information (including credit card information) and Social Security number were not impacted."

Please note, the bolded text above was done by BleepingComputer to illustrate the difference between the two notices.

For customers whose financial information was exposed, T-Mobile is offering a free two-year subscription to the myTrueIdentity online credit monitoring service.

For customers who did not have financial information exposed, T-Mobile is not offering anything.

While the data breach notifications do not indicate that passwords were accessed, I strongly suggest you change your password at t-mobile.com. If your original password is also used at other sites, you should change them there as well to a unique password.

All customers impacted by this data breach should be on the lookout for targeted phishing scams. These phishing scams could pretend to be from T-Mobile or use the accessed information to gain your information at other companies.

It is not known how many T-Mobile customers were affected or when the breach occurred.

BleepingComputer has contacted T-Mobile for more information but has not heard back as of yet.

Prior T-Mobile data breaches

In 2018, T-Mobile customers were affected by a data breach after an unauthorized user hacked into the T-Mobile systems.

During this attack, the attacker was able to gain access to customer names, billing ZIP codes, phone numbers, email addresses, account numbers, and account types (prepaid or postpaid).

T-Mobile suffered another data breach last year that affected its pre-paid customers.

As part of that breach, an attacker gained access to the name and billing address (if provided when establishing an account), phone number, account number, and rate plan and features of pre-paid customers.