ATT has changed the account passcodes of millions of its customers after it confirmed a massive data breach that saw personal data leaked on the dark web.

ATT said in a message on its website on Saturday that it was reaching out to 7.6 million current customers and 65.4 million former customers whose personal information had been compromised in a data leak involving sensitive personal information such as names, phone numbers, addresses, birth dates, ATT account numbers and passcodes, and Social Security numbers.

It added that the compromised data appears to be from 2019 or earlier and does not contain personal financial information or call history, and encouraged customers to remain vigilant by monitoring account activity and credit reports.

Related The company said that customers past and present whose information was involved in the leak will receive an email or letter explaining the incident, what information was compromised, and what ATT is doing in response.

If you have an active account impacted by the security breach, ATT will have already reset your passcode. In a precautionary measure, the company is strongly advising the rest of its customers to change their ATT passcode if they havent done so in the last year.

Heres how to do it:

1. Go to your myATT Profile. Sign in, if asked (if you have extra security enabled and cant sign in, select Get a new passcode).

2. Scroll to My linked accounts.

3. Select Edit for the passcode you want to update.

4. Follow the prompts to finish.

Note: Refrain from using character combinations from previous passcodes.

To assist customers, ATT said it is offering impacted individuals complimentary identity theft and credit monitoring services.

Check out ATTs website for more information on the data breach.

ATT isnt the only major mobile carrier to be impacted by such incidents. T-Mobile, for example, was hit last year in a breach affecting 37 million of its customers that saw customer names, billing addresses, email addresses, phone numbers, birth dates, and account numbers stolen.